Bbc cast iron intake questions
 

I'm not class racing I'm just trying to go fast with stock parts. I have a 427/390 up intake on my 454. Has anyone modified the plenum to look like an aftermarket intake? Also would like info on carb spacers with a stock intake. I already had a dean oliver quadrajet and the car runs great I'm just looking to go faster. Thanks

Re: Bbc cast iron intake questions
 

You don't say what type of car but, if it's not a corvette (hood clearance) get an after market intake. I run the 427/390 Corvette manifold (aluminum) because I have to and it is a piece of junk.

Re: Bbc cast iron intake questions
 

I didn't know the stock stuff was that bad. How would it compare to a performer if the plenum was modified.

Re: Bbc cast iron intake questions
 

Haven't run an aftermarket on this car but usually they're good for 20 hp.

Re: Bbc cast iron intake questions
 

Don't hack on the stock manifold, it just isn't worth the time or effort. Besides, hacking on the plenum could result in horrific mixture distribution problems, that could result in engine damage.

Just get the Edelbrock 7164 or 7561, and be done with it, you'll be time and money ahead.

We're not allowed to run spacers on stock intakes, so I doubt you'll see any data here for that either. But if you just bolt on one of the Edelbrock intakes, it won't matter, you won't need a spacer.

Re: Bbc cast iron intake questions
 

Thank you guys. I appreciate the help

Re: Bbc cast iron intake questions
 

Edelbrock performer rpm and performer rpm air gap are good manifolds to use over cast iron oem manifolds. Putting a 4 hole spacer on top of them will also help if you have the room. If you have to use the oem manifold it can be modified to work better than stock.

Re: Bbc cast iron intake questions
 

Well that's what I'm wondering. What's the way to improve a stock manifold. Cliff Ruggles swears by the stock Pontiac manifolds. I know it might be apples to oranges but they can't be that different. I see the Pontiac guys grinding on the cast iron a lot.