Does any one know about bore motors over .30?
I think you mean 0.03 oversize (30 thousandths). Boring the engine is not a do it yourself job. Disassemble the engine and bring the block into an automotive machine shop. They have the precision equipment to bore the engine perfectly round and square. After that just buy a set of .03 oversize pistons and rings and reassemble. The 455 was used by all the GM divisions. They just gave it different names. Mine was in a 72 Pontiac. Sometimes I got as much as 8 MPG.
