MountainHound

I put on the old 79' head. I replaced the rocker arms, pivots and bridges. I put the lifters in the same locations one at a time and they looked fine. The cam also looked fine. The rockers and pivots did not. I changed the oil and filter and there wasn't any shiny metal this time. I believe the metal was from the rockers. After putting the old head back on I have no noise from the valve train or lifters. I believe the problem was the 4.0 conversion head and the push rod length and pre load. I checked the timing from your advice and the chain is within spec. What a good way to check! The distributor driven gear is also good. wear pattern is good. So I need to get a new exhaust going to do a good road test. All the tests I did were at idle in the street with only a down pipe with no cat or muffler...my neighbors are really cool haha. I talked with clifford on the valve cover. I had to grind the flange around the bottom and file to make it fit. No leaks yet. I am hoping it works for a while This valve cover is 3'' higher than stock so it interferes with the throttle cable and the thermostat. I got a spacer from hesco for the thermostat and the throttle cable moves ok but still doesn't look like it will ride that way for too long. I have taken a couple of pictures that I will upload and update after I have the exhaust in place and do a true test drive. Thanks again!!

Thanks Moses! I took the 4.0 head back off yesterday. I pulled the lifters out and they all look pretty good. The one I believed to be sticking isn't dished or showing any unusual wear and the rest look surprisingly good. Doesn't mean they are though but will reuse them. I also looked at my push rods, rocker arms and pivots. Push rods are fine. Five rocker arms and pivots are worn to where I cannot see the oil channels anymore. Checked the oil again to make sure nothing big and shiny was in there. I didn't see anything this time but I am sure it's in there somewhere ha ha. I have decided to try to make the 79' head work for now at least until I can get the reman. So a few replacement rockers and pivots and a couple of gaskets and I'll see what happens. I will hold onto the head, valve cover and header for now. My buddy has a Cj and may want to give the swap a go. Thank you for the advice on this. I will do some more research before purchasing the later model engine. I have read there are two different timing chain covers so I will pay special attention to crankshaft stick out and the pilot bushing. My current setup works so at least I have something to go off of. I would be bummed if I got it all together and had clearance issues and would hate for the pulleys not to line up. I will update my progress and let you know how it goes....It would be nice to keep the 79' going for a while but I may be kidding myself Josh

Thanks for the advice Kevin, If I have a good manual I can get things figured out....but swaps are a bit tough for me. Fixing up an old Jeep teaches you a lot. Good luck on your repairs. I think if I can get the right motor to mate with my T-18 figured out I will go with a reman. I do like the fuel injected 258 a lot. I use the Jeep mainly light to moderate crawling and isn't a daily driver. The fuel injection helps with the long trips though. I won't go back to a carb at this altitude. Not looking for a v8 or expensive stroker build. Need to fill in my profile. May help with my post Thanks again

I have hit a sticking point with my engine upgrade on my 1979 Jeep CJ-7. After 8 years on running a carb I finally fuel injected my CJ. I installed a Hesco MPFI kit and Genright tank with an in-tank YJ module. My old tank was rusted and after installing the tank and new lines the fuel pressure was and still is good. The rest of the install went well and I did all the work myself. I also purchased a new '83 exhaust manifold with the O2 bung. I could not find a good replacement valve cover for that year 79' and the old steel one leaked a lo so to continue the build I purchased a 4.0 head, exhaust, and valve cover which solved the leaky valve cover issue and a few other clearance issues. I also believed this to be an upgrade after the research I had done. After installing the 4.0 head the problem I faced then was not getting the right pre-load with the pushrods. I reused my 4.2 push rods, rockers and bought new bridges. After encountering this issue I stopped on the build for a while. Watched the video on getting right valve clearance, pre load etc... and bought an adjustable push rod. Well then I got deployed and the Jeep sat. I think my next mistake when I got home was to fire it up. When I started it The valve train was noisy and I believe I have a bad lifter on No. 1 exhaust. I changed the oil to find shiny metal and the Jeep idles rough and low rpm. I think this was due to the incorrect pre-load coupled with the Jeep sitting, and me turning the key. So with that said I am at a cross roads with where to go from here. I have contacted a few rebuild shops to diagnose my issues and fix my pushrod problem. They say the short block may be toast and I should look at a reman. I am looking towards that too. Only one shop will actually look at it but it is in another city. The CJ has a manual T-18A with a 1980 scout dana 300. Which year 258 would mate to my drivetrain? I still have the exhaust for an '83, intake, accessories etc.. so I am thinking an '83 reman. I would like to have an aluminum valve cover as well. Advice?