Currently have a 3 speed Saginaw transmission in my 1974 Camaro. Would like to upgrade to a 4 speed. Can anyone tell me the correct transmission and number that would bolt in? Thanks/Lee

 

any saginaw type three or muncie car 2wd and shifter will fit in the car if you need a new shifter this one will work only if you include your original shifter arm for the console if you dont have a console then only minor trimming for reverse to go far enough

http://www.summitracing.com/parts/sum-700000/overview/

as for transmission codes
https://www.nastyz28.com/2gcog/trans.html
has areally good breakdownof what came in the car the only real diference between them has to do with shifter bolt locations ie. a 65 impala muncie/saginaw has a strap style shifter (bigger) where as the camaros wer bolted directly to the case (slimmer)