Originally Posted by chevy454
Is the 6L80 similar to the 4L80? Ie, does it take the same parts to upgrade them both? I have a buddy in Michigan that did R&D on transmissions for Borg-Warner (until he was layed off last month) so he knows all the GM trannies in/out and has built race trannies of all breeds on the side for years...
4L80 = 4 speed
6L80 = 6 speed
automatics are automatics. clutch packs, planetary gears, sun gears, etc. there's just more of them in the 6l80 compared to the 4l80.