i got access to a th350 out of a late 70s truck, its setup for 4wd, whats involved in changing the output shaft so i can use it in my trans am, is it even worth it?

all i need to know is if anything besides the actual shaft needs to be changed

AFAIK you don't have to change the shaft to set it up for a 2WD application; only the extension housing. But of course it will then be a short-shaft one, not the correct thing to go into one of these cars without a different drive shaft; and of course you'd have to deal with the torque arm somehow too.

The 4wd shaft must be replaced. It is too short to be used
with even a 6" tailhousing. I did the opposite shaft swap about
a month ago. I didn't even have to loosen or remove the pan
or valve body because I was able to pull the band across the servo pin. You will need a front pump lip seal, o-ring and gasket
as well as a case of tranny fluid. It would be a good idea to change the dipstick o-ring or seal, too. BTW, is your car set up to
use a TH350?

forgot to mention its not goin in my thirdgen its goin in my 80 trans am i already dealt with all the bull**** to put the th350 in my 87 camaro, called up thirdgen resource to get the driveshaft, thanks for the piece of mind guys