ok, so im in the process of deciding if my 20r/22r hybrid or my 350 chevy will be used in my 1980 pickup, if i use the 20r, i have the option of using the stock 4 speed for a little while, (reverse is going out) and its got 289K miles on it, or a auto from a newer truck, (not brand new, but like 1986 or so,) if i use my 350 chevy i have a muncie, but i will trash the axles, so i want to use the hybrid if possible, my question is, how much power would i lose using the auto tranny? i think its somewhere around 20% but how much do you lose with a 4 speed? cause i plan on running 33-35's with this engine and 5.29's

thanks
wade

 

the problem with the auto is that i think you need to hook up an ECU...maybe find an auto from a carbed 2wd truck and use a divorced adapter?

then again, you could get a w56 or a similar tranny for as much as the divorce adapter. either way(newer 5 speed or 4wd auto) you're going to have to change your drivelines since everything got longer in '84

 

EDIT: sorry to raise this one from the dead, forgot I was looking at a search. Its been one of those days.