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I know your a hardcore 4.0L, especially stroking one, kinda of guy, but I hear far to many folks say that the AX-15 can not handle V8 (300hp, 300 ft lbs +/-) over time...but some say it can. Would like some input from the "Jeep God" himself. Seems other forums are just opinon.
Got a lot of dirt track friends with access to cheap SBC's, Ford 302's and such. 

Thanks again.

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Wayman…The AX15 in “new condition” can handle 300 hp and 300 ft-lbs torque.  They do hold up when in top condition and not subject to abuse.  This unit is on par with an NV3550.  Neither is exemplary, both will handle horsepower and torque in the range you describe.  I would say they are less robust than a “World Class T-5” from the 302 H.O. days, but not by a lot…300 ft-lbs is not extreme.


Advance Adapters does a brisk business on V-8 adapters for the Jeep/AX15, if that’s a good indicator.  There are many conversions out there.  In my later builds, which lean toward “truck” type gearing and ratios, I’ve opted for the NV4500, which eliminates any guesswork.


I am not averse to a SBC or Ford 302.  For Ford, I do prefer a 351W for crankshaft stamina, and both the 302 and 351 have the distributor conveniently at the front of the engine. 


There are emission requirements for swaps if that’s an issue in your area.  The Jeep stroker 4.6L works well, and the only “modification” beyond that is the use of 302 Ford V-8 24-pound injectors.  Everything else should work…To produce 300 horsepower, however, requires a bigger cam and compression, which may make emission tailpipe readings go sideways.  I use the milder CompCams 252 grind with 8.7:1 compression, and tailpipe readings fall within norms.


The inline six produces an altogether different kind of power.  You’d like the 4.6L stroker better for bottom end torque and a quick torque rise, useful for off-road driving and for fuel efficiency at cruise…Apples and oranges, if you want brute horsepower, there’s no substitute for cubic inches: a SBC, G.M. LS or Ford small block V-8.



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