I run 12.5 Ross domes in my street 440.It did have 516 reworked heads.Now it has Stealths with .039 gaskets.It will run all day long on pump gas.Only time I get clatter is if I really lay into it in like 1st.It has a Comp .588 cam with IIRC around 325 duration.Now when I really want to have fun I add 112 race gas.Same thing at the track.Rocky