305 issues and I need help!!

[droe71]

Ok I just replaced a quadrajet with another quadrajet that was off a 1984 corvette. I bought a regular sized quadrajet gasket for it. The other gasket that was on the old carb was a bit more thicker than the one I replaced it with.

Now when I turn the egine on I get this terrible hissing that soulds like maybe coming out of the carburetor and then the engine stalls.

Should I have kept that old thick gasket the carburetor is plugged up pretty good and it was not making the hissing sound before. I am at a loss.

I wish i could upload the sound it just sounds like a loud hissing coming out the engine and it stays on for about a minute and then it stalls. 

[78 Chevyrado]

Spray carb cleaner wherever you think it may be leaking.  Use the straw so you know where you're spraying and go easy on it.  when you find the leak the carb cleaner will make the engine run different and there's the leak

[Josh454]

Is there maybe a port on the new carb that you forgot to plug?  With a smaller gasket did your bolts bottom out and keep it from sealing?  Other wise, as already mentioned spray the area with carb cleaner.

[VileZambonie]

Don't even bother spraying carb clean. You already know you have a vacuum leak. If it's not a vacuum line you forgot to hook up (vacuum booster, pcv etc) take it back off and check the base gasket along with the mating surface.

[Jim Rockford]

I've never had any luck with thin qjet gaskets, I have never had any issues reusing the stock thick gaskets,

[Irish_Alley]

I aint never used the thick gaskets always used the thin ones. But like vile said if you have all the lines checked the base of the carb I had a Holley that one ear was bent on it making it sucking air like that

[droe71]

Hi Guys thanks for your replies. I actually bought a fel-pro gasket it's about a quarter inch thick. I went and replaced the thin gasket with the fel-pro and man did it make a difference.

I am up and running and I even did a little peel out it's not much but I was at least excited about it. LOL!!

Next thing is fixing the leaky valve covers. Anyhow this wannabe mechanic is extremely excited and looking forward to getting this shorty up to par.

Thanks again
Aldo

[Irish_Alley]

i ain't never had any luck with cork valve covers i would finally get them fix only after screwing with it a bit but i put rubber ones on my truck now they were a bit tricking since they kept on coming loose at first but i think they are ok now