I have a C-6 automatic in my 88 f-250 7.3 idi diesel. yes i love the C-6 tranny, good and tough. but it sure sucks the fuel. I want to put a 6 speed manual from a newer 7.3 powerstroke in my old 7.3. will it work?? if not can any modifactions be down? has anyone else done this

 

https://www.ford-trucks.com/forums/833386-zf-6-a.html Have a read through this thread. Plenty of good info.

 

Well I just read it as I am very intersted and it less than a bolt on swap for sure. I would think a ZF-5 with the correct diff gear would be a better route.....IMHO