Thanks for the reply I currently have a vintage Carter AFB 625 cfm on the engine, I'm thinking of getting a ~700 cfm double pumper when I start to hit the track again. The valve springs are the Hughes #1110 I believe they are straight single w/damper, 110# on the seat and 315# at .500" lift or something along those lines so shouldn't be an issue there. As far as the exhaust the headers can't breathe properly as the guy who welded it in (not a performance specialist for sure) used the puny <2" collectors that came with the headers instead of 2.5" like I asked. The downpipes have lots of sharp turns of course and are now smashed up from the road pretty bad.