Transmission Swap question

[saskgreen]

Hey guys, I am sure this has been talked about lots before so perhaps a link or just info would be good. I currently have a sbc and a 3 on the tree. Looking to put in a rebuilt sbc and a different transmission. Looking at a TH350 or TH400.

Are either one of these a direct swap? I have the two piece drive shaft. Anything you would beef up on those transmission's prior to putting it in? Looking for basic install without to much modifications. Will be on a budget so figured one of those would be best, sure a 6 speed would be cool, but I believe the price goes up lol

Thanks in advance.