84 Z28 Factory Aluminum Intake Or Gm Iron Spread Bore?

I've got about 370hp in a sbc in a 4000# Wagon, small Elgin pro-stock 1120p cam, bored 40 over (357cid), dish pistons, 041 64cc heads, estimated 9:1 comp, 2 1/2" aluminized exhaust, 2 1/4" Dynomax turbos, Edelbrock 1406 carb with a performer intake. This combination works very well but there's always room for improvements!

I also have a 70 truck iron spreadbore manifold and a factory 84 Z28 305 Aluminum intake at my disposal.

I'm perfectly happy with the setup I'm running but would like to hear some opinions about which intake might make a little better hp for my application.

I drive hard and let no grass grow where I go. I didnt build this thing just to look at and it gets driven!


Register now (free) or login to remove ads

aluminum... better heat disapation, lighter, and factory aluminum is cool...

What kind of wagon is it?

What headers are you running?

The Performer is a little better, performance-wise, than the OEM intakes, but not by much. If it were me, I'd keep it, just to save on gaskets if nothing else.

Cast iron is heavy (obviously).

You need to re-think your compression ratio. Domed pistons and 64cc heads on a 350 = well over 9-1, closer to 10.5-1+. Any stock intake would be a step backwards.

I stand corrected folks, my pistons are dish not domed. That would make my compression about what I first stated. Sorry

Thanks for the correction Nova72.

A stock car builder said they experienced a better flow with the iron intakes back in the dirt track days. My engine builder liked the iron over aluminum due to the lack of flexing and gasket wear out with aluminum and heat exchanging.

I kind of like the 305 factory one but how much diff over the Edelbrock? Just because it is an original GM might not be worth the effort to change it out?

Thanks for your opinions!

My Wagon is a 2wd 53 Willys dropped 4", th400, 373 open gear 10 bolt, block hugger headers. Basically 70 Chevelle running gear. 54 Chev 1/2tn straight axle w 11" disc conversion, Toyota power steering, you know how things just kind of fall together when you're having fun! The weight is 2200#s on the rear axle and 1800 on the front. If I had posi I'm afraid I would pile it up right off the bat? Don't drive in the rain for that reason. Power braking just skids the front tires so a line lock would be useless. 245x50x15 Euro ta's front and 295x50x15's rear. Never ending project. All but body parts available at u-pull it! Looked for a rod with character and then along came this flat fender Willys for 800 bucks in 87. Well over 15 grand in it by now, who cares as long as it makes my day! Next biggie would be a big block and wheel stands after I win the lotto!

Enjoy the ride.