I don't think you could mill the 317s enough safely to run them N/A. There are a few though that have run them unmilled in FI applications though.

As far as higher compression and FI, yes, it is shown that a lower CR allows you to run more boost without fear of detonation, but there are plenty of trucks with LQ9s (10.08:1 CR) running moderate levels of boost with no problems. Keep it under that and you should be okay.

 

thanks for all the info. it looks like these arent the heads for me.

i also checked out that website for a quick minute and couldnt find the section you were talking about. ill look again now that ive got more time but could you send me a direct link to the specific page you were talking about so i can check out the specs on the rest of the ls-1 based heads. thanks again