Awhile back I posted about a new build I had finished up. Basically, 355 with stock highly ported base, port-matched SLP runners and plenum, AFR 180s and 276 HR-12 cam. I know my headers arent the best and that the intake manifold is holding me back. But I was pretty thrilled with 305rwhp, and my first time to the track I ran a 12.82@104, but my best mph run I hit 107. After reading some of the threads here though, I'm beginning to think maybe I should get an aftermarkt base and port it, along with better headers. I'm also running a 2400 stall and I know I could use a bit more stall as well. I was thinking about supercharging, but for the money I've decided I'd rather just maximize what I have here. I guess I thought I was doing pretty well results-wise, but now I'm thinking I'm not using my heads/cam to their full potential. Thoughts?

 

Well I would have bumped the compression to 10.6:1 with the AFR Eliminator heads. They have an improved combustion chamber with a dual quench pad that can handle the extra compression with no problem. I bet you could run around with 87 octane and "light" throttle. So there was probably 15 horsepower or more left on the table.

That said yes an after market base and opened up runners will increase your power and rpm band. I'm not familiar with the Mac headers so I cannot comment on them. However at 1 5/8" they may be blocking some of the exhaust port on the AFR heads. If so that will cost you some power. No problem with the 4" Mufflex system.