hello, i have a 91 bird 305 with a edelbrock performer tbi intake manifold with a open air element. I just wanted to know if these things would make a horsepower difference. if anyone could let me know how much horse it adds that would be great.

 

With no other mods, not much, it works well with future mods though. I would say no more than 3 HP on a stock engine, maybe less. Once you add a FULL EXHAUST from the HEADS BACK, a Cam, ported heads, ultimate TBI mods, chip tuning, it will make more of a difference.

The stock TBI manifold is not that bad, I have pulled 279 RWHP with a stock aluminum TBI intake.