Im no expert by any means,
but, i'm running a built slant with ported cast iron head with larger valves, holley 390/offenhauser intake/hooker headers, 10.5:1 compression, custom comp cam with 280 duration... thing pings like crazy on 91 octane pump gas at idle or under load. right now im using 4 gallons of 110 racing gas with 3 gallons 91 and it runs good. im trying to ween it down to as low (cheap) as possible.. will let u know when i get there
:burnout: