Installing At Transmission And Buick V6

Recently I bought a 1972 CJ5. Mostly for the hard top to put on my 71 CJ5. As I start checking it out, I get this crazy idea to put my spare odd fire engine in it and an automatic transmission. So with the 72's radiator being set farther forward and the three extra inches added to the front end. I figure my odd fire engine could be moved 5 inches more forward then the 304 in it now. That might be enough for a 700r4. Of course it might be more work then I can handle though it almost seems just right. Also I like the lower angle of driveshaft with the Dana 18. That also might help when running a short drive line.

 

If you're going to keep the 18 you'll need a different (offset) rear axle.

 

Actually there is a 3 inch longer wheelbase and the front clip is 5 inches longer. So the wheel is 2 inches further back in the front fender opening compared to the earlys. The earlys tend to catch the front edge of the fender on the tires, and the intermediates catch the rear edge.

It is possible to hit the oil pump cover of the 304 with the front axle, so be aware of that with your V6. Make sure you don't place it where the top of the pumpkin can smack it.

Sure you could do it, but I'd keep the Dana 20. If you want to go cheap, use a TH400 - that way you can do it all with junkyard parts. Save a few hunerd bucks. It'll take a long time to make that back from the extra fuel you'd save with the lockup/overdrive transmission. (Sorry - I was thinking 304 - see below). Most of these CJs have 3.73 gears - so the TH400 would be fine on the highway - and you don't need such a deep crawl ratio with an automatic.

 

If you want to bolt a TH400 to the 225, you can use the BOP pattern TH400 from a Buick-Oldsmobile-Pontiac-Cadillac car of the right vintage, and it will bolt to the 225. Jeeps with the 225 or 350 used the 2-piece case, which was the old Buick nailhead transmission plus an adapter ring. There is also an internal part that fits on the front of the torque convertor to adapt to the crank pocket. Finding replacement torque convertors and flex plates for these nailhead transmissions may be difficult. You can have old torque convertors rebuilt... not sure what you'd do for a replacement flex plate. Parts for the Buick case TH400 are widely available. I recall all you need is the Jeep transfer case adapter and the right Dana 20. The GM output shaft matches the 20 (?) splines of the transfer case input gear made for the TH400. If you buy an adapter from Novak or whoever, it will probably have a six-spline output shaft to match the usual manual transmission Dana 20, but you will have to take the transmission completely apart to install the new output shaft.