Well we are picking up an hd trans for the diff and cover but I think this is a great time to build up a trans for when I dive into building my car. First off can I use a non tap-shift trans in my comp g? I have never used the tap shift and would be fine if it werent functional. What can I do to this trans other than a rebuild, single chain, gear ratio, and axles? I helped, more like watched, my bf build his th400 going behind a turbo 5.3. We did all sorts of things like a 32 element sprag, clutches, full manual valvebody, transbrake, stall converter, and drilling stuff and leaving parts out :s. I know alot of this isnt necessary but what kind of potential can our transmissions have without breaking the bank? I plan to drop to a 2.8 or 3.0 pulley on e85 someday after I get another dd. My boyfriends running john deere hygard hydraulic oil in his trans and claims it takes heat much better and changes his stall speed?? To be honest I dont know what alot of this means but what do you guys have for Iinput??