can someone please tell me why I cant just put a 20b to my na trans and rearend, how much horsepower can they handle before will what ever you guys call it die,heel over,fall to little pieces inside,lol....just curious i only want to run like 400 horses any way on my daily cruiser

 

the na trans will take somewhere between 200-250hp depending on how you drive.

mike

 

dump the clutch = replace the gearbox

 

If you only want 400hp, I'd just stick with a 13B BFT @ 20 psi. A lot easier than a 20B swap and cheaper too.