I think the major problems your going to have is passing emmision tests (spelling?). A small block of any size will be simple swap. The 350 is a good choice. The next question is how much power are you looking for? or should I say how much to you want to spend??
balace the rotating assembly, victor Jr. intake, Holley Dbl pump. (600cfm or more?), equal length 1 5/8 primaries into 3 inch collectors, changing the plugs will be a pain in the a**, even with angle plug heads. A remote oil filter would be a good thing. I have some knowledge of racing those 3rd gens.
You might look for a 3rd gen BB, this one is mostly 1st gen guys. good luck