just to say it in advance, excuse my ignorance about carbs.

i've searched a bit on this, and haven't really found anything addressing my question....

I'm going to be buying a 80's cutlass supreme, but for the sake of discussion, it's got a 700-R4 and is going to have a 350, so we'll pretend it's a thirdgen, ok?

my "camaro" that i'll be purchasing doesn't have a motor (was supposedly hydralocked by the previous owner....wtf? ), but the body and interior is flawless, and i know the owner (he purchased it from the first owner as a project car, but is getting rid of it), so i'm going to assume he's telling the truth about the tranny.

i've got a 1985 suburban with a ruined body but pretty solid motor and tranny, which will be the donor of the motor.

i have no idea about the motor, as far as what heads and cam it's got, perhaps 416 heads and a just a truck-ish cam. it seems to be the stock motor. pulls hard off the line (and falls on it's face up top), and very torquey, i'm going to guess about 230 hp at most.

now, i'm thinking about doing the following:

the "camaro's" original motor has a quadrajet (i'm assuming....it's stock) 4-barrel sitting on top that i'm going to hold onto. the suburban also has a 4 barrel (again, assuming quadrajet) sitting on top of it.

i'm thinking about trying to find an older bolt pattern dual carb intake, and cheaply, if it's even possible. of course, i'm thinking about just running without the ECM and running dual quads. i know the tuning will be a bitch, but i've done carb tuning before on the suburban and i'd be willing to spend a lot of time tuning it. and i've already got the carbs and 2 single carb intakes, in case this experiment proves to be a bad idea. my biggest question is if the heads and cam would even move air well enough for this to effect performance at all.

keep in mind that i'm going to have headers, dual gutted cats, and dual flowmasters, so basically a true dual exhaust setup with very little back pressure, so the motor is going to have potential to move air well.

this car is going to be a daily and winter driver, so i'm not going to go buy an aftermarket carb or intake. i'm ideally hoping to find a junkyard intake, if that's possible. and the winter factor is going to be irrelevant, because this motor was optioned on the suburban with an electrical engine block heater (which i'll be keeping on the motor), and it's always started and ran perfect in the winter, provided i plug it in overnight.

so my main questions are:

1. will the stock heads and cam flow well enough for dual quadrajet quads to even enhance performance over a single?

2. what cars (if any) could i expect to find a old-boltup dual quad intake on? if not from the junkyard, where could i get a used one?

3. since i'm going to have the motor out on a stand for a while, i'm thinking about a rebuild from the heads and up, and i'm contemplating just doing a DIY port job on the heads with a dremel, and buying an aftermarket non-roller cam (which i don't know a lot about....any suggestions for a mild non-roller cam?). if i did these mods, would it be worth it then?

thanks a lot for the replies.

 

A 750 CFM q-jet will adequately feed a 350 to over 7400 RPMs. Think your Suburban 350 will be winding tighter than that? I don't.

The factory, to their credit, never put more than one q-jet on an engine at a time. Several months ago somebody here dug up a picture of some aftermarket dual q-jet manifold - search if you like. I've never seen one in real life.

In real life, a single 4-barrel carb will perform better than dual quads on a street engine.

Don't even need to be talking about a 3rd gen for that to be true.

 

https://www.thirdgen.org/techbb2/sho...hreadid=247140

 

thanks for the link.

that intake = $309.69

no thanks....i'm going with a single.

 

dual quadrajets will so overcarburate that engine you will never get it to run correctly, even if you did find an intake (not likely) for 2 spreadbore quads. That thing would bog and blow smoke to high heaven, it cannot handle 1400CFM and can't possibly move enough air to get both carbs to meter properly.

Find a decent aftermarket manifold, and run the original q-jet from that engine. With minor fiddling, it will work very well. Save the other Q-jet for parts. Trust me.

Troy
So Cal

 

No matter what the four barrel, usually a single four barrel (if its the right one) can outperform the dual quad setup. Also its a lot easier to tune and ha$ other Benefit$.