If you are going to do a turbo on a stovebolt, I would suggest going a step further and installing fuel injection, then you can control timing and boost with the computer too.
I've got a Jimmy 302 in my garage that I'm working on gathering the parts for- I'm going to do a MegaSquirt II fuel injection on it, using mostly GM parts, get it running well, then add a 4-71 blower and volvo intercooler to it. I figure with stock compression it ought to take to the boost pretty well. Its going to replace the 261 in my truck.
