recently bought what i was told was an unmolested 4 bolt 400 short block. After disassembly i discovered that the block had been bored .040 over. Just wondering what the safest compression ratio and power output i should shoot for. I want as high as possible and still be on the streets. CR is not an issue as i work at a gas station that sells 112 octane leaded by the pump. i had originally planned on boring it .030 over with CR of 11.5-12 to 1. i plann on all roller valvetrain. Also are there any ways of strengthening a 70's factory block? any information is appreciated!