Engine Stamp Pad Questions

The difference between a 383 "R" engine (regular fuel) and a 383 "HP" engine (premium fuel) is , as you may know , is the compression ratio . The "R" engine has dished pistons to run on regular fuel . From your description you have a "HP" engine . It's just fine as long as you use 93 or better fuel . I would pull the heads to see if it has hardened exhaust seats . this is important if you want to run pump gas . good luck