I just purchased a 1977 with a 402 BB under the hood, i havent actually picked it up yet. My question is what size transmission is in it or how would you identify it. One of the problems is that the gear selector does not work it stays in drive, could it be an easy fix or internally to the transmission?

 

thats not original so its hard to say what they put in it.if the modulator valve is on the rightside rear its a 350 turbo,if its towards the front on the rightside its a 400 turbo.if it has a kickdown cable going to the carb its a 350 turbo.if it has a electrical hook-up on the leftside about the middle of the transmission its a 400 turbo.as far as not shifting,make sure the cable isnt broke and make sure all the linkage is hooked up

 

Transmission oilpan identification: