Yes, you can use the 307 pistons. They have the proper bore and also the required Compression Height so they do physically work. Wether or not they raise your compression and by how much depends on the size of those reliefs. I would bet though that it raises your compression. Which is always good for a boost in efficency (power).
I picked up some 307 pistons for my 250 but I may have messed up (ebay) and instead gotten LS1 pistons. Physically they fit, but they need a longer rod (difficult, but makes a better engine) and they may not have the rigt pin. We're going to see if I can make them work. Maybe not. Any other questions?
God doesn't like ugly.
