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1995 Dakota Engine and Transmission Swap


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Moses, time to pick your brain again. I picked up a 1995 Dakota, v-8, auto, 4x4 with a bad engine dirt cheap. Im thinking, if i can find a complete wreck to get all the parts from, that when i do the engine, swapping the trans to a 5 speed at the same time. My questions are, which transmission would be better fo this swap, the AX15 or the NV3500? Also, did they use the NV3500 in the dakota, and if so, which years would be a direct swap for the truck i bought? I know i need the engine wiring, trans wiring, ECM, pedals, clutch interlock, clutch master and slave cylinder and hose, and gauge cluster, but will i also need to change the interior wiring harness as well?  Final question, what years, and what trucks, vans, and SUV's can i use the 5.2 from for the 1995?

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Hi, Biggman, great to see your post and learn about the latest acquisition! 

 

The manual transmission swap on a '95 Dakota can involve electronic concerns like the PCM, so you'll need to consider how far you want to go with this conversion.  The V-8 swap could be a 5.2L or even a 5.9L V-8 from a Ram 1500 or a Dakota (5.2L).  There's the option of using the V-8's automatic transmission in the process.  The Dakota did offer a 5.2L V-8 in 1995, so there's a prototype here.

 

Regarding the AX15 versus an NV3500 or NV3550 (Jeep version), they offer approximately the same torque rating.  Jeep and Dakota use both types, Jeep changing from the AX15 to NV3550 in 2000 models.  Interestingly, the Ram and Dakota trucks show an available NV3500 transmission in 1995, so both transmissions were apparently available at that time.  The bellhousing-to-transmission pattern for an AX15 or NV3500/3550 is the same.  (I adapted a Jeep NV3550 to a Buick V-6 by using a Toyota A150 to Buick V-6 transmission bellhousing adapter.)  Both use the "8" shaped bearing retainer.

 

The NV3500 was used behind the 3.9L V-6 and 4.7L V-8 engines.  In the Ram 1500, the NV4500 was the transmission of choice, and this iron case monster is light years more stout than the AX15, NV3500 or NV3550.

 

So, if you're serious about a V-8 and manual transmission, the 4.7L would be the limit for the NV3500.  An NV4500 can handle up to one-ton truck capacity, including Cummins 5.9L diesel power, and that would be the optimal transmission for the torque of a 5.9L V-8.  Something to consider.

 

We can explore this further.  I'd emphasize again that the electronics do change between these engine and transmission combinations.  That can involve wiring harnesses as well.  It might be easier to get a powertrain with a 46RE or other transmission that can line up behind an LA 5.2L or 5.9L pushrod V-8.  Electronics might be less challenging, since the Dakota 4x4 did at least use the 5.2L V-8 and an "RE" series automatic transmission in 1995.

 

Sounds like the price is right on the '95 Dakota, and I know you like this model...Several ways to go!  We can explore the PCM part numbers and wiring harness numbers.

 

Moses

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Moses, thank you again for your time. I do want to keep the truck a v-8, like it is now, but i think i am just going to stick with the 5.2, because i am afaraid a 5.9, even in a dakota, will kill what gas mileage it already has, and for what we are going to use the truck for, i dont think i will need the extra power of the 5.9. I just need to figure out which years i can use the 5.2 from, and which models. As for the swap to a manual, i decided instead to leave this one automatic, that way my wife and brother can also drive it, since neither of them want to learn how to drive a manual trans vehicle. I think instead, i am going to turn the 1994 into a minor project, since it has recently developed some major issues, such as a blown head gasket, as well as ongoing transmission issues with the AX15, which i may swap to an NV3500, since they seem to be more plentiful in my area.

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Hi, Biggman100...I understand the decision to simplify the restoration of the '95 V-8 model 4x4 Dakota.  Sticking with the current setup and an automatic transmission will make your engine replacement much easier.

 

First, I would keep the current induction and exhaust system to simplify the engine change.  As for what 5.2L will fit, consider any truck/SUV 1992-98 5.2L Mopar pushrod long-block as a replacement.  A long block simply needs to accept the peripheral parts, and the Dakota long block is similar to a Ram truck or Jeep Grand Cherokee.  The 1991 Ram truck engines with MPI/EFI may also meet this fit.

 

As long as you maintain the existing induction/injection, exhaust and ignition system, you will just swap over any details like the oil filter stand, water pump or fan and clutch, etc.  Unless the '95 Dakota 4x4 V-8 does not have all of its pieces in place, this should not be a challenging engine replacement.

 

If you elect to use the 5.9L, we could compare PCM and other details to see if additional components need to be included.  Possibly not, as the injectors are the same for both engines.  PCM and other pieces might also be the same or at least work interchangeably.

 

Should you need specific part numbers, I can furnish details for a Mopar long block replacement into a 1995 Dakota, including any additional interchange parts guidelines.

 

Moses

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Moses, the truck is complete. The guy i got it from was using it to haul a small enclosed trailer, and either blew the oil pump shaft, or the pump itself, because he drove it about 60 miles with no oil pressure, popped two rods through the oil pan, had it towed home, pulled the plates off it, and sold it to me the same day. A couple questions though, based on what i would ultimately like to do with it, at least for now, which is to just find a good low mileage used engine through the salvage yards, and do a direct swap. The issue is, the salvage yards say i can only use the 1995 Dakota 5.2, or the 1994-1996 5.2 from the ram. I am looking for a complete engine, minus the alternator, power steering pump, and A/C compressor, so all i have to do is pull the original engine, and drop in the new engine, hook everything up, and be done with it. You said the 1992-1998 5.2 will fit, but what all might i have to change, depending on the year of the engine? I know the 1992-1994 5.2 looks exactly the same, so i cant see why the salvage yards would say they wont fit, unless sensors are different, and the injectors seem to be the same from 1992-1998, as well as the distributor, and crank and cam sensor, so i must really be overlooking something there.

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So, my first approach was a long-block replacement.  If you want a direct, complete replacement engine, the differences would be exhaust and emissions pieces and hookups, PCM changes, tuning and sensor settings, exhaust system differences and so forth. 

 

The 5.2L roller lifter V-8 engines fit three distinct platforms:  Ram truck (1992 MPI engines to as late as 2003, according to Mopar catalogs, we know that 1998 is a reliable cut-off); Jeep Grand Cherokee (1992/93-'98 5.2L V-8); and the 1992-up Dakota 5.2L MPI V-8 pickups.  Of course, 4x4 models use different transmissions than 2WD, there are these considerations, too.

 

Note: When a recycler tries to identify direct, complete engine swaps, they rely on interchange manuals.  The manuals in recent years must take into account the emissions requirements for an engine swap.  In some states, like California, the engine swap cannot involve an engine older than the chassis.  That could be the reason they insist that you must use a '94-'95 Dakota engine; for California, it would have to be a complete '95 engine.

 

If you do want a complete engine swap, you're likely left with comparing parts between your engine and the recycled engine(s) being offered.  Also, you need to consider whether your emissions inspection will be a problem with an earlier or later engine installation.  Newer would be okay, however, states like California consider this a "swap/conversion" and not simply a "replacement".  Technically, in California anyway, you would need a referee station inspection and special sticker, even to put a later engine in the chassis. 

 

So, there are two big concerns around a complete engine swap:  1) emission legality and inspection, and 2) actual parts interchange.  A huge difference is OBD-II (1996-up) versus your 1995 PCM system.  1996 is the first year for OBD-II (self-troubleshooting) computers.  Your 1995 chassis does not have OBD-II.  This could be a major issue, as your engine and chassis wiring will not interchange with OBD-II sensors, and certainly not with the PCM plugs, and there would be a different type PCM  (Chrysler "JTEC") from 1996-up.  For a complete engine swap, you may be limited to 1992-1995 engines for this reason.

 

Obviously, the best way to play it safe would be a 1995 (maybe '94 as well) Dodge Dakota 5.2L V-8 if you want a complete engine swap.  If a long-block or semi-complete engine is feasible, you have many more options.

 

I looked at the 5.2L V-8 long-block listings directly from Mopar Reman:  All 1992/93-up 5.2L Jeep and 1992-up 5.2L Dodge Truck roller lifter engines use the same long block part number through 2003.  (Cylinder heads are interchangeable for all 1992-2003 5.2L MPI engines.)  Clearly, the Jeep Grand Cherokee 1992/93-98 and Dodge Truck 1992-2003 have interchangeable long-engines and parts. 

 

Note: 1985-90 roller lifter long blocks interchange with each other but not later. 1991 is a "mystery" or transition year. Truck 5.2L V-8s still use TBI in 1991. 

 

This means that the manifolds, injection, distributor, water pump and all other peripherals may have differences, but the basic 5.2L V-8 long engine is the same from 1992-up.  If you were to replace just your long block and use all of your existing 1995 peripherals, you would have a wide cohort of 1992-2003 5.2L pushrod V-8 engines as a source.

 

Moses

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Moses, again, thank you for your help with this. It is greatly appreciated. One thing i do want to clear up, just in case anyone comes across this, and wonders about the 1991 engines. The 1991 uses completely different heads, intake, and ignition, than the 1992 and up, which means that you cant use the 1990 or 1991 v-6 or v-8, unless you swap the fuel system (the 1991 has 2 lines on the pump, and is TBI, whereas the 1992 and up are MPFI, and only have one line on the pump), electronics, PCM, wiring, intake, exhaust and a host of other stuff. The reason i know this is because i have had 2 1991 Dakotas, one a 3.9 4x4 (which i still have, its the red and silver one), and the other a very hard to find 5.2 4x2. Even the salvage yards and hollander say they didnt put the 5.2 in the 1991 dakota, but, anyway, with the 3.9, which is still have, i blew the engine, and wanted to use the1992 and up engine for ease of interchange, because hollander says that the 1991 is a 1 year only engine (which, after doing the swap, i found the 1990-1991 3.9 and 5.2 are the same ignition and fuel system), but after i looked into it, i found the differences between the 1991 and 1992 setup were so vast, i figured it wasnt worth all the work involved. The 1990-1991 v-8 is pretty much the same setup as the v-6, with the same problems involved in swapping to a later v-8.

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One thing i forgot. I did some actual visual comparisons on certain gaskets, such as head and intake gaskets, and found that for this swap, the intake gaskets will only work from 1992 to 1996, with the 1997 to 2003 intake gaskets being different. The head gaskets are the same from 1992 to 2003, so the difference must be in how the intake is made, but that shows, at least to me, that to use the 1997 to 2003 block in the 1992 to 1996, you would have to swap the heads from the 1992 to 1996 to the 1997 to 2003 short block. Now, if only i could do the same comparison on the 3.9 engine, since i have either a bad head gasket, cracked head, or cracked block on my 1994 3.9, and the salvage yards are saying i can only use the 1994 and 1995 3.9 in that truck, but no one around here has those gaskets in stock. Rockauto says the head gaskets for the 3.9 are the same from 1992 to 2003, so maybe, if i do need a short block, i can get a newer engine with less miles, which i would prefer to do, i just need to find a way to verify the info from them.

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That's interesting about the 5.2L heads.  According to the 2010-2011 Mopar Reman catalog, they use the same cylinder head part number from 1992-2003.  Part number R5852480 fits all 5.2L Magnum engines.  Presumably, these heads are rebuilt from OE cores, and they come without the rocker arms or head gasket.  If rebuilt/exchange, Mopar will accept and rebuild any of these cores and send them out to fit atop any 1992-2003 short engines.

 

Note:  There are instances where a manufacturer will sell a "universal" replacement head that interchanges or supersedes with several earlier casting numbers.  These heads would be "crossover" designs that bridge the changes in head and manifold design over the years.  Sometimes, a "remanufactured" head is actually a brand new, universal replacement type head casting.  The best way to compare cylinder and block castings is by actual casting numbers on the cores—period.  An automotive machine shop's guide to casting numbers will break out the year and application.

 

If the Mopar Reman catalog is accurate about the 5.2L V-8 heads fitting from 1992-2003, then your theory about the intake manifold must be the concern.  The intake manifold gaskets might accommodate changes in the manifold design:  port sizing, manifold threaded ports for coolant, vacuum or other fittings, gasket improvements, injector fit, added fittings/ports or whatever.  (The manifold part numbers for 1996 versus 1997 might provide a clue here.)  For cylinder heads and manifolds, casting number comparisons are the best criteria.

 

Regarding for the 3.9L V-6, the 2010-2011 Mopar Reman catalog again shows the 1992-2003 3.9L V-6 Magnum engines in the "Trucks, Vans and Jeep" section as only one cylinder head part number for all of these years: R5639480.  This is the 2010-2011 catalog, and unless Mopar has updated the information since (call your local Mopar/Ram dealer parts department or check out an online genuine Mopar parts source), you once again have a cylinder head (minus rocker arms and head gasket) that apparently fits all of these years...unless there is a universal new casting flowing into this parts stream.

 

Note: Since Mopar does require a core on these 3.9L and 5.2L heads, logic suggests that the cores are being rebuilt and shipped out to fit all 1992-2003 short blocks.  Unless, of course, there is a universal new casting being used in place of the OE cores.  This can occur, and again, the casting numbers are the most reliable way to break out differences in design and applications. 

 

If you need the intake manifold part numbers for the 5.2L or 3.9L over the 1992-2003 period, I can look them up...

 

Moses

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Moses, after spending a couple hours at a U-pull yard today, i found out that the intake is the same for 1992 to 1997, and has some significant differences from 1998 to 2003, at least appearance wise. I also found that the earlier intake (i used a 1994 intake) will bolt right up to the newer heads (checked the fit on a 2000 durango), all the bolt holes line up, it appears that all the openings in the intake line up as well, but, i found that things like injectors, TPS, Iac, and most of the components on the 1994 intake dont match the corresponding components on the 2000 intake, at least when it comes to the harness connectors. The other thing i noticed is that the earlier intake gaskets are thicker than the newer ones, although i dont see where that would make that much of a difference ultimately.

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Good work, Biggman100!  The harness and connector differences could reflect the emergence of OBD-II.  With Jeep, the 4.0L XJ Cherokee had a wild-card year: 1996.  The transition to OBD-II was awkward, and the engine wiring, wiring harnesses and connectors for 1996 are often unique to the 1996 XJ. 

 

In the case of the Wrangler, we can note that there was not a 1996 model made!  This likely was to keep the 1995 YJ Wrangler and its non-OBD-II emissions alive while the 1997 TJ Wrangler emerged with the new OBD-II PCM, wiring harnesses and other accommodations.

 

There may also have been a "transition" for the 1996/97 Dakota and Ram trucks as they moved into OBD-II requirements mandated for the 1996 model year...In any case, your findings are very useful!

 

Thanks...Moses

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  • 5 months later...

Moses, i actually ended up going with a 5.9 swap on this truck, only because i picked up a running, but undriveable due to major frame issues, and no title, fairly low mileage full size Ram Van free. The guy who owned it, an older gentleman who is friends with my neighbor, bought a property in a tax auction that had a whole bunch of vehicles, tractors and farm equipment that the previous owner, who passed away, just left sitting all over, and he wanted the property cleaned up, so he made a deal with me to clean the place up, get rid of all the vehicles and junk, and said i could keep anything i wanted from the property. We put a battery in the van, and it started pretty easy, seemed to run good, didnt have any oil leaks i could find, didnt overheat, so, i figured why not do the swap. A few things i found in doing the swap though, is that there are some pieces you have to swap from the 5.2 to the 5.9, such as accessory brackets, alternator, A/C compressor, power steering pump and bracket, engine wiring, and ECM, as well as using the 5.9 torque converter, but, for the most part it wasnt any harder than just replacing the original 5.2. The exhaust manifolds bolted right up to the Dakotas exhaust, and the Dakotas bell housing was a direct bolt up as well. The 5.9 has been in the Dakota about 2 months now, and i have noticed i get only slightly worse gas mileage than the 1994 with the 3.9, but, i get much more power, especially when towing, so, i guess the swap was worth it, even though i was originally against that swap.

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Biggman...This is valuable detail about the conversion to a 5.9L V-8.  I was intrigued by the "slightly worse" gas mileage over the 3.9L V-6 in the '94 Dakota.  I've always believed that a smaller engine simply cannot get good mileage when overworked.

 

For clarification, this is a 5.2L V-8 to 5.9L V-8 swap—not a 3.9L V-6 to 5.9L V-8.  The Dakota is a 1995 4x4 V-8 chassis.  Which transmission do you have now, and does that work with the torque from the 5.9L V-8?

 

Thanks for doing the lifting here, others will benefit greatly from your homework!

 

Moses

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  • 2 weeks later...

Moses, yes, we swapped the blown 5.2 in the 1995 4x4 with a 5.9 from a 1995 van. We used the original A518 transmission that was in the truck, and bolted the 5.9 to it. So far we havent had any issues with it at all. We have also used that truck for logging in the woods, using low range quite a bit, and it has held up very well over medium sized rocks, and very muddy and slippery terrain without any glitch in shifting or slow speed holding either. We dont really beat on it, and mainly use it for normal driving, so i cant say if the transmission will hold up under any abuse, and with it being recently finished, i cant say yet how well it will hold up long term either. Only time will tell.

 

As for the gas mileage question, yesterday we took both trucks on a 386 mile round trip to move a friend, and the 1994 with the 3.9 and 5 speed averaged 24 MPG, and the 1995 with the 5.9 and automatic averaged 21 MPG. I dont know if i just got lucky with both trucks, but they both seem to get, at least to me, amazing mileage on a tank of gas. For a comparison, my old 2000 Durango never got better than 18 MPG combined, and my sister's 2001 2WD 3.9 Dakota seems to average around 19 MPG. I have heard though, the 1997 to 2004 (third generation) Dakota does average worse mileage than the 1991 to 1996 Dakotas.

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This is good mileage in either case...Often, a bigger engine can often save fuel in a working truck. 

 

I have always liked inline six-cylinder engines for their inherent balance and torque potential.  Long-stroke engines like the Chevy 292 or Ford 300 produce very good torque.

 

Years ago, the Chevrolet/GMC 292 inline six was one of my favorites for torque output and dependability, although its piston travel was debatably threatening to the life expectancy of the engine.  Despite its many merits, the 292 seldom outperformed or delivered better fuel efficiency than the over-square 283, 327 or even 350 V-8s.  The Ford 300 inline six, with tremendous torque, often used more fuel than a comparable truck with a 302 V-8.  Sometimes, "There's no substitute for cubic inches!"

 

Sounds like the Dakota 3.9L V-6 has a lot going for it.  Not sure how the weights compared between the two loaded trucks.  If similar, the 3.9L V-6 certainly did a respectable job!

 

Moses

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I would say the weight in each wasnt too different between the two trucks. It was mostly boxes of stuff, clothes, electronics, a couple of stands, and not much else. He left all his furniture, so that wasnt a consideration. Most of this was highway miles, and not a lot of city or back road driving, which also helped the mileage numbers. One thing i have noticed with the 1994 though, is something i consider very odd, and that is that it seems to get better mileage with the chrome steel factory wheels, than it did when i had the aluminum factory wheels on it. Both trucks have the same 30/9.50/15 goodyears on them, so i know tire weight isnt a factor, i just find it hard to believe that the aluminum wheels are so much heavier than the steel wheels.

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  • 1 year later...

Hi Moses. I know we have went over this a few times, but, when i went back over what we covered, i only found info on the 3.9 heads, and the entire 5.2, as to what will interchange with what, so, i just wanted to clarify one thing with you. Is the info for the 5.2 short block, that it is used from 1992 to 2002, the same as for the 3.9l v-6? The reason i am asking is, i thought i blew a head gasket in my 94 Dakota, but, after taking the heads off, i found that every one of the water jackets where the head bolts go, are cracked all the way through, on both sides of the bolt hole, and, finding an older (1992-1996) short block is near impossible around here, however, i can find a ton of 1997-2002 complete engines and short block's all over, so, im hoping to just get a newer bottom end, and drop my heads and intake on it.

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Wow, biggman100, that's too bad about the bolt holes and cracks in the 5.2L block casting!  Strange place to crack, sounds like either over zealous torquing of head bolts or freezing, this must be before your time.

According to the Mopar Reman catalog, the 1992-2003 5.2L Magnum is all one part number.  (The 5.9L Magnum is also a single 1993-2003 listing.)  Cylinder head castings may have changed but not the short blocks.  This makes sense, as these are all Chrysler MPI engines with serpentine drive belt crankshafts.  Not much could be different, the short blocks especially.

There are no catalog distinctions about short block model applications, so any Mopar 5.2L Magnum short block from this era should interchange.  Reman engine catalogs are a good reference; the reman shops accept any core from this model era.  Once rebuilt, the short block has to fit all other model applications in this model year group.  

Moses

Edited by Moses Ludel
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Actually, the problem is with the 3.9 v-6 block in the 94, not the 5.2 v-8 block in the 1995, so, what i am looking for is interchange info for the 3.9l v-6. I am assuming, since the 3.9 is basically a 5.2 with 2 cylinders removed, that the interchange info for both the 3.9 and 5.2 would be the same, but, i don't want to go through the work of getting a bottom end, when i will have to pull the heads and intake myself, before i can get it, without knowing what year bottom ends i can actually use.

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Ah, in that case the 3.9L short blocks, according to the Mopar Reman book, are the same from 1992-2003.  1988-91 is in its own class.  There is distinction on the gasket sets as to "Pre-Magnum" and "Magnum" engines.

If the short engine you find is a Magnum like your 1994 (1992-2003 era), you should be fine.  Magnum cylinder heads differ from the earlier heads, I would guess this has to do with carburetion or TBI versus the MPI engines from 1992 and newer.  For those unfamiliar with this Chrysler 'LA' pushrod engine design, here's the breakdown of the 3.9L V-6 and applications:

Displacement 239 cubic inches / 3906 cc Bore and stroke 3.91 x 3.31 (90 degree V6)

Valves Overhead - 12 valves, roller followers, hydraulic lifters

Fuel injection 1987: None, Holley carburetor

1988-1991: single point electronic FI (TBI)

1992-1996: Multiple-point EFI/MPI

1997-end: Sequential, returnless multiple-point FI

Construction cast iron block and heads

Compression ratio 9.1:1 in 1997

Redline 5,250 rpm

Fuel 87 octane unleaded regular

Oil, coolant: 4 quarts oil (plus filter and filter oil?), 14 quarts coolant (unknown vehicle application, must vary?)

Emissions 3-way catalyst, two heated oxygen sensors 

EPA mileage (1997 Dakota)16 city, 22 highway (2WD, manual transmission)
15 city, 18 highway (4WD, automatic transmission)

Any 1992-2003 3.9L V-8 OHV Mopar short engine should work as a replacement for your 1994 3.9L V-6 short block.

Moses

Edited by Moses Ludel
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I actually answered my own questions on this, but, for anyone who comes across this, I have verified that ANY 1992 to 2002 3.9l or 5.2l magnum long block can be used as a replacement. For the 1992 to 1996 truck, using a 1997 to 2002 long block, you only need to swap your intake, flywheel\flexplate, crank sensor, and, in my case anyway, the fan, due to the 1998, 2001, and 2002 I compared, has a slightly smaller fan, but, all the engines I compared were in 2wd trucks, so, that may be why the fan was smaller.

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Yep, the heads and long blocks for the 3.9L V-6 are the same from 1992-2003.  Heads may interchange back to the first 3.9L V-6 Dakota engine, I could not confirm this, though.  (Short blocks break out as pre-1992 versus 1992-up.)  Safest bet is a 1992-2003 long block. 

Manifolds do differ and are expected to come off the old engine...

Moses

Edited by Moses Ludel
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