Has anyone used a 2 barrel aluminum intake from a 79ish 302? I was thinking of installing one that I have for weight saving etc. Do they breathe any better? I was going to run it with the egr plugged off. I was using a mid seventies carb spacer with the egr plugged off but it burned through, so I installed a 289 spacer with the pcv hole at the back, and it sure runs nice. So, I wasn't sure if installing the aluminum intake with the egr plugged off would be a good idea.......what do you think?
IMO i'd say dont waste your time just get an actuall performance 4bbl aluminum intake. theyre not any harder to put on and $50-100 will get you a really great used one any emissions era 2bbl intake, no matter what its made from, iron or aluminum, probably isnt going to net any noticable power gains
I hear that, but I like 2V carburetors. I thought the factory aluminum 2V might flow and perform a little better.
The biggest thing you have to look at is starving your engine for air. The 2v carbs that I have seen usually don't go above 500-600 cfm. That is one of the advantages of going to a 4v. In some cases a 4v carb is actually more fuel efficient then a 2v if you use a 600 cfm carb you will find you will have better acceleration, more power and as good if not better fuel economy. (as long as you don't race from light to light) If you are going to keep everything stock then you will be just fine keeping the 2v carb, of course two or three 2v carbs work just as good as a 4v
Trust me, three 2 bbl carbs work far better than a single four. The aluminum stock 2 bbl intake is dead on the same as a stock four bbl intake, only difference is the carb pad.
Back in high school I ran a 2bbl aluminum intake that we "ported" ourselves (me and a freind using his dads dremel) an old fireball II cam and a 2bbl from an old 390 that we rejetted (the holley jets fit) and adjusted and a set of old mustang headers. That thing ran like a whole different animal. Also gasket matched the intake & exhaust ports on the heads(we had no money it was all old crap laying around that if we spent $50-$75 would be alot. I was actually considering trying something like that again now. I say use what youve got you might be pleasantly surprised. Robb
That's what i like to hear; it's how a lot of things were done in the early days before you could just go and buy performance off the shelf. I would like a set of aluminum heads as well -nothing crazy, even stock ones if they exist. I figure with heads and an intake (aluminum), it might be enough weight saving so I can keep my 6 cylinder coil springs, but raise the front end closer to where it belongs (just did the 302 swap)
Personally I would pick up a used 4v aluminum intake. If you just really want to keep a 2v carb, just get the plate style adapter. That said, a very small, vacuum secondary 4v carb will gain power and economy over a 2v carb. You can get a 4v that has smaller primaries to drive around on, and with vacuum secondaries, you can set them up loose to function when the engine wants the extra volume, or tight for economy. Just a thought. A small 4v carb is best of both worlds. If you use the aluminum EGR intake, block off the exhaust flow at the head surface. Many intake gasket sets include metal exhaust crossover block off plates. And if you get a set that doesn't, they are very easy to make out of tin. This will keep the exhaust out of the intake totally.
Blocking the exhaust passages at the heads has two benefits. One is keeping the hot gasses out, the other, lesser known, is preventing those nasty gasses from eating right thru the aluminum. That she-ite ain't pretty. I've had two FE factory intakes that suffered from the "Exhaust Cancer" One was a tri power, the other a 428PI.
that is a good piece of knowledge (exhaust blocking) and the carb info. I have seen some cool 2 barrels though, like the holley 350 and 500 cfm 2V and the 2V road demon. I have seen the adapter you are speaking of as well. lots of choices anyway.
View attachment 28308 here is what were talking about -a spacer that burned through. i swapped this baby out with a 289 unit
I ran a holley 500 cfm two barrel on the streets and man did it drink the gas. I noticed a little difference but not much.
part of the problems I have found with the 2V carbs is that you have to make it so it runs across all ranges decent. Usually it has to be a little richer than a 4v carb, due to the fact that it has to produce an adequate ammount of fuel for acceleration, for cruising, passing ect. The 4v can have smaller primarys as ratio411 says and use the secondarys just for acceleration. With a vacumm secondary carb it only uses the fuel when the motor demands it.
The Holley 500 was never meant to be an economy carb. It's whole purpose was 4 bbl perfomance in a 2 bbl package. I've used two of em on 4 different engines and they made a big difference on all. Of the 350 & 500, the 350 Holley is the stock replacement carb.
