Detonation on a BBC

[Chevy454]

You guys would be real surprised at what the actual compression ratio of a STOCK L-72 is! Believe me, it's NOT 11:1! The deck clearance on dad's L-72 was only .013", and the heads were shaved .010", and when the dust settled, it came out at a whopping 10.2:1. Scott Tiemann did a DEAD STOCK L-72 last summer(?) for a Berger car, and it came in at 9.8:1.

Now, if a guy does a lot of decking/shaving, and gets some healthy pistons up in the holes, then you could get wild on the compression ratio. I'm not saying you can run straight 87 out of the pump, but premium gas and mix some octane boost or racing fuel with it, and you will be fine.