8.1L/ZF6 to 454/4speed swap


New member
Feb 3, 2013
Hey y'all. I have a 2002 Chevrolet Silverado 2500HD 4X4 with a 8.1L Vortec and the ZF S6-650. The truck has 194k miles and I have had it for 6 years. I love my truck. I have done a lot to it over the years making it my own and do not want to part with it. That being said I have had some issues with it also. I have not had 6th gear since I bought the truck and I have had numerous issues with the engine also- mainly being oil consumption. I have been researching this engine and the more I hear about it the less I want in in my truck. I'm tired of putting a gallon of oil in it every week and I'm tired of trying to fix what GM misengineered with the intake and the heads and PCV system and all the other issues with it. And no one I've found locally know anything about this German transmisssion and from what I hear it's a throw away transmission if you need hard parts- which I'm sure I do. So I'm contemplating just ditching the 8.1 and the zf6 and just building a from the ground up 454 carb engine and an old school 4 or 5 speed trans that is more common and easier to work on and get parts. I was wondering if anyone else had done this or has any idea what all is involved as far as modifying engine mounts, universal joints or drive shafts, and anything else involved in doing this. Also I have to pass emissions testing where I live and I am wondering if a setup as described will pass emissions testing somehow. Thanks in advance.