Hey Jimmyz, that looks just like my '74 coupe. Same condition too. Body off on a dolly. If the block is in good shape go ahead and splay the caps. Not a problem, but probably an added expense. In the SW Ohio area there are still a good number of 4 bolt blocks available. I built a 500 hp 383 this winter for my C3. Just buy a forged rotating assembly and don't assume it is balanced. Have it balanced at a local quality speed shop. The factories do sometime make mistakes. Your local guy will more than likely catch them. Good luck.