My 73 Monte Carlo (3800 lbs) with 11.5:1 350 would detonate slightly. i indexed the spark plugs and solved that one.

My 68 427 Vette (3200 lbs) at 11.75:1, oval port heads required 50/50 mix of premium unleaded and 108 leaded race gas (what a pain that was).

I have not ever seen a formulation with CR as a function of weight, although it seems plausible to me. 10.5:1 is approaching the gray area perhaps, but a retard function ignition module, either open or closed loop, would probably fix you up. If was real bad, but before race gas, you could inject water also.

I think in the end you build it and see though .........

Regards, Kitz