I have a Weiand Xcellerator single plane intake, and its just annoying..... It likes to cause backfiring at higher rpms and an idle thats giving me nightmares. None of these issues I had when I had the Edelbrock 3704. The shop I go too said that the single plane is just too much for my 305. Here are some dual planes I was looking at. I have no EGR and aluminum 113 corvette heads. http://store.summitracing.com/partde...1&autoview=sku http://store.summitracing.com/partde...4&autoview=sku Either of those good? Or any other opinions on what to get.

Currently running the Performer RPM with the square flange. The plenum divider is cut down. Really runs decent.

With large TBI units (2" bores) the spread bore flange is most likely better. I bought this manifold way back when still running a carb. I had to grind the sides the plenum/mounting flange to get the wide TBI bores to smoothly flow into the plenum.

Also running '113 heads, I run coolant through the crossover. Drilled/tapped 1/8" NPT into the crossover near the heads area. Using fittings and 3/8" hose allow coolant to circulate under the plenum.

This improves driveability. The setup also draws cold air from the cowl area. So a little heat under the plenum helps.

RBob.

Kinda confused about the coolant crossover? I thought that coolant already flowed through the center crossover?

Im justing using the stock 305 throttle body, and I have an adapter plate. Ill check fitment with whatever intake I get and grind anything that gets in the way.

So you think the Edelbrock 7101 Performer RPM is the way I should go?

Get a Edelbrock Performer RPM Air-Gap, since their debut i have heard nothing but good things about them. Out of every manifold comparison i have seen the Air-Gap whoops that ***. Hot Rod compared it to many intakes and the Air-Gap did the best. Even with peak power it almost did as good as a Victor manifold, but had way better bottom end than a Victor. Unless you have a full race application an Air-Gap is the best choice in my opinion as with many others.

But would the air-gap be too much for a 305?

there are a bunch of people on here that know more about engines than me, but i dont think it would be too much since you have different heads and a cam.

Would be interesting, how your 3704 would perform with 2"bores and a nice crossflow grinded between the 2 bores. The plenum size and the runners look wery similar on the other Edelbrock manifolds.

On carb manifolds the crossover gets exhaust gases. The exhaust comes from the heat-riser (now EGR) passages in the heads. The '113 heads do not have these passages. It is a flat mounting area to block off the crossover on the intakes.

This makes it easy to run some coolant through there.

Note that this coolant improves driveability greatly. And is not possible with an air-gap style intake manifold.

RBob.

I have an RPM Performer if you need one, you would just need to elongate the center bolt holes though (it's for '86 heads and down). I'm switching to a single plane for my TBI, but then again I'm also switching to port injection, but keeping the stock LO3 throttle body....

I used to run a Holley street dominator intake on both my Chevelle street car and my 87 Camaro race car and the holley intake peformed better that the performer rpm ever did. I never tried the performer rpm airgap, but i know that the street dominater had better intake ports and was 1" taller than the performer rpm and would pull to 7000 rpm's. My car ran very high 11's with a .040" over 350, .515" cam, unported 186 heads, 4 barrel carb full length 1 5/8" primary tube headers, 4.10 gears, manual shift th350 tranny w/3500 stall and 28"x10.5" slicks. The engine I'm currently building for my truck is going to be using a fully ported Performer Rpm Intake with tbi adapter till I can get another street dominator. A friend of mine owns a cylinder head shop and he has told me on several ocasions that edelbrock stuff is good but you have to alot of work to it to make them as good as they can be.

No need to elongate the center four holes to bolt it to '113 heads...

RBob.

Apples & Oranges.

RBob.

You mind posting a picture of what you did? I get it, but id like to see how you did it.

I ordered it already yesterday
Otherwise I woulda just gotten it from you.

Will do. If you don't see them here by end of day Thursday, PM me a reminder.

RBob.

Yeah, I just seen that. Thought he was running the '92 stockers at first....

No problemo, you would have gotten it for only $50.00 from me though....

OK, we have pictures. The drivers side pic shows the feed from the thermostat crossover water passage. This side feeds into the intake manifold crossover.

Then a close up of the passenger side fitting in the intake crossover.

The last picture shows the return plumbed into the heater return line.

The hose is common 3/8" fuel line. The fittings are from a home box store.

The T fitting in the heater hose is aluminum. Made from some tubing using the aluma-weld rod and a propane torch.

RBob.

So I connect the thermostat crossover to one side of the center passage. Then hook the end coming out the other side of the center passage to the heater hose?

That is how I did it. The thermostat crossover is the hot water source. The heater hose line is the return. There are other ways to plumb it. Just need to have a feed into the crossover, then a lower pressure return to the pump.

Could also feed the water from a head opening at the rear of the engine. With it returning to the thermostat crossover. That is more along the lines of how GM did it with the TBI intakes.

RBob.

sorry about hijacking this for a second my new intake doesnt have the crosover in the back or the center. Im not shure what to do about that it does have wholes in the back should i just rount it stright across to the other side? And do i have to make a air crossover if im using the dual plane intake and tbi?

Which intake and heads are you using?

RBob.