Advice on which heads to use. 360 , 302???

One last thing. You don't have to pull the heads to swap valve springs. You can buy a valve spring compressor and air hose attachment to inject air into the cylinder to hold the valves in place then use the spring tool to take them apart and swap them out. I even made my own valve spring tool with just some scrap metal I had. It's not the prettiest thing but works real good. It bolts down where the rocker shaft bolts down so it's easy to use. Here's a couple pictures