I wanna know how man cfm the stock quadrajet??

 

Around 750 or so if you modify the secondary air valve limit tab.

 

By making this mod, what will I gain? Horse power, torque? I would like to know how to do this. Never done it before.

 

On a stock 305, you wouldn't gain much if anything.

On a 305 with cam, exhaust, air cleaner & heads upgrades, you would see a little more horsepower.On a 350 with cam, exhaust, air cleaner, and heads upgrades, you'd see a significant gain.

 

I'm just not sure what the previous owner did to the engine. I have had 2 different gear heads tell me they can hear a cam in my engine. I don't know what to believe. It sure runs quick for an lg4. I hit redline fast and it wants to keep going. I have to back off, don't wanna blow the motor.

 

Gotta watch you don't blow your manifold!

Seriously what has been done to the car? Given stock converter, and exhaust, with any cam you could "hear" it would be running like a complete turd.

Putting a cam with a noticeable lope in a LG4 and seeing a gain from it would require changing nearly everything but the short-block. Otherwise it's a huge mis-match of parts that would fall on it's face.

 

Maybe off topic-
But how d you do this?

 

It could be an HO cam which would probably just require new springs. It does not sound like a pro stock. I was told you could not "hear" an HO cam. It runs nice and strong, and could blow away a turd any day. LOL Manifold isn't leaking either. I always thought it was bone stock, and I still do.

 

How do I do what?

 

blowing the manifold is a joke.. it's a line from "fast and furious" that i always found amusing.

I'm not challenging that you have a HO cam or not, I'm challenging your gear head buddies hearing a cam. Like i said if you had a cam you could "hear" and all else stock it would be a real slow boat. And no springs in the world are going to change the other restriction that would limit such a cam's potential.

You can find the secondary air valve restriction tab on the passengers side of the carb up on the top back where the secondary air-valve linkage is you can work with your hand; it has a green rod going through it from the pull off valve. If you work it with your hand and pay attention you can see a tab on the linkage underside that stops it from opening further. Take a file and shave it down just slightly and check the play working it with your hand. You don't really need or want to go over 90' open, 80' is probably best.

 

Ah ha! I never heard of blowing a manifold!! Ya got me dude. Anyway, I didn't think you could hear the cam in an HO either. I'll try the linkage thing.