I have a one ton International step van with a six in line AMC 258 and a 3 speed manual tranny. I am looking in to swaping that tranny for an automatic or 4 or 5 speed manual tranny but I need help with figuring what tranny would connect behind the venerable 258 six in line without the use of an adaptor. Hope someone here has dealt with amc engines and knows a direct bolt on tranny for this engine. Thanks guys for any help.
Do you just want a automatic transmission in general or do you want a specific make chevy/dodge or do you want one with an overdrive? The 4.2 AMC motor never changed bell housings and when they updated the block to the 4.0 motor the bellhousing remained the same. Knowing this all of the jeep transmissions behind a 4.0 will fit all the way up untill 2006 when they discontinued the inline and put the stupid minivan transmission in the wranglers. But in the late 90s they went to computer controlled transmission so you will want to keep the older ones. So with this information you can look for the AMC version of the Chrystler Torqueflite 999 transmission will work that was installed in jeep CJs Wranglers, Cherokees, Wagoneers, Grand wagoneers and J series trucks from 1981 to rougly 1996, you must have the AMC version internally the AMC and the Chrystler transmissions are identical but they have different housings cast for the different bolt patterns. But you can go for the older AMC automatic transmissions also there are some TH400 transmssions floating around with the AMC bell housing on them, the bellhousing between the V8 and the I6 was the same. These were installed in some of the cars too so if you see an AMC in a wrecking yard you might get lucky and find a AMC th400 which is a bulletproof but power hungry 3 speed. Honestly for you the easiest one to find would be out of an early 90s cherokee with a 4.0, but I think one of the hardest parts about what you are looking for is a 2 wheel drive transmission there arent that many 2 wheel drive jeeps out there.
