Hey I got a pretty stock 91 360 in my 72 and raced a 70 ss chevell the other day on the free way. Don't get me wrong it was damn close but once I was about half a car length ahead I let off. We were at 120 and I'm not pushing my car any faster on public highways. I do think it was a clone because it didn't sound like a big block more like a well built 350 Idk if all the 70 ss were big block or not.