I know a guy who changed the stock 330 intake to a Edelbrock performer RPM intake and replaced the quad jet with a Edelbrock 750. He also added aset of Lightning headers. He claims he picked 4-500 RPM and as much as 5 mph. Is this possible? And if so, could the same results be had with Stainless Marine exhaust or EMI thunder? Could you see a rpm gain without changing the exhaust at all? Would just changing the exhaust be a bigger increase than intake and carb.

Thanks

5 mph sounds about right, the 330 had a restrictive manifold on it plus the headers makes a good package. by themselves maybe 2 mph for each

In my opinion your buddy did the right things right off the bat. Not necessarily the cheapest, but the most effective. Exhaust upgrades are the best bang for the buck, with induction upgrades being a close second. The headers are the best if you can afford them (they are a bit pricey), but the EMI Thunders are a definite improvement from the stock stuff.

Jeez, everyone is usally pretty opinionated about 454 upgrades. Must be a bummer weekend on account of the crappy weather in the midwest.