Anyone think that 11.25 compression ratio is doable for a street car with aluminum heads on pump gas. Is this reasonable?

yes

I'm currently using stock Eddy heads on my small block with 10:6:1 compression and no problems with 93 octane, in fact, I've been thinking of trying 89 octane and maybe some timing adjustments to see if it pings any. Quench is the key for higher compression - .042" is best if I'm thinking correctly.

My sons stroker 500 is running Eddy heads with 11.25 CR and what I would call a middle of the road duration street cam (Not sure of exact numbers). It runs on the 92 oct we have here but when he goes to the track and flogs it he usually puts in about 10% race gas. I think 11.0 to one would be better for a street/pump gas motor, again depending on the cam and other factors.

Lots of overlap(108 lsa) and a lot of duration?

INTAKE EXHAUST

ADV DURATION 307 318

DUR @.050 250 263

LOBE SEPARATION 113

DEGREED to 110

This is what Scott Brown speced for my stroked 440. It has RPM heads, .044" quench. Comp of approximately 11.3-1.

It runs fine on premium, and has a nice lope to the idle.

codfish