I am new to this and needs some info I have a 71 cutlass 350 someone stole my original transmission can a transmission from a 80s model cutlass fit on my 71

 

The 1980s cars used two different automatics, the TH200 three speed and the 200-4R overdrive four speed. The TH200 bolts in, but it is a VERY weak trans. I wouldn't waste my time. The 200-4R requires some work to install, but the O.D. is nice to have. It too is marginal strengthwise in stock form behind a 350 Olds motor.

Frankly, TH350s are a dime a dozen. Just get the easy replacement trans.