I've previously installed the plenum and runners on 2 different cars in the past. Once on a 350 and once on a 305. Both times I got very impressive results(with the stock base). That being said, I was really anxious to see how well it worked on my 91 305 using an edelbrock base(which I ported to match the superram runners). So I got it buttoned up fri nite and have been "road testing" it since. After 3 days of driving around, there is NO noticable difference! What I'm wondering is, is it possible that with the increased airflow from the intake combined with no cats and the 4th gen loudmouth exhaust that it is outside the stock parameters of the speed density system?? I'm gonna call Josh at JS performance tomorrow about doing a custom tune on it. Should I try an AFPR to bump up fuel pressure? Any input greatly appreciated!

 

Btw, both previous cars were MAF system.

 

Yes, the tune could be way off performance wise.