Ahso, I forgot about the AL heads.With aluminum heads, compression ratio can be almost a point higher vs iron cylinder
heads given the same combo...
So 10:1 with alum heads is fine with 87 given modern engine controls, etc
Now in the old days about 10:1 is premium octane required with carb, dumb ignition, etc
I love aluminum !! So much lighter. My Small Block Chevy in my Monte SS is an all
alum block (aftermarket block) & alum heads.. It's 11:1 and I'll hit it with 175 nitrous
all on pump 91 octane fuel with no issues..
A lot of times it's the quality of the fuel, not just the octane rating... That's what is
******* engines. From my understanding the fuel around my area - Midwest/KC
is not the best quality. So I generally run some diff types of additional additives
when I know I'm towing hard with my Yukon or just running my stepside/corvette/monteSS
really hard. This hobby is expensive !!!!
OK, I will quit worrying again.