where would be the limit for a carb'd 408? I know the efi guys run 11.5:1 and are fine, is this the case on a carb set up as well? thanks pump gas motor fyi.

 

no one has any thoughts just my guess is that I'll have to run less like 10.5:1 or so.

 

I've ran 11.5:1 compression on carbed small block chevys before using 93 octane and never had a problem. It's really more a matter of DCR.... Cam timing, quench, etc. I am building a carbed Gen III 383 and will be running around 11.3:1 compression. It will be on pump gas too and I don't expect any problems. I'm using a TSP Giant cam and LS6 heads. You need to run your #'s to find out DCR......