Why not a piston from a 350" - thats 4" bore.
Speaking of old chevy highperformance, I am doing a cam swap on a Buick Regal that has a sbc in it and backed up when opening the hood to find angle plug heads, the '292' turbo head. First set I ever saw - the owner had no idea about them so I educated him in case somebody tried to take advantage of him.
