Let me start off but saying I like quads and I know a lot of people dont, so if you don't like them please don't just tell me they are junk and walk away. Ok I have a quadrajet rebuild by holley in the mid 90s but was never reinstalled. I believe it's an 800 cfm judging by the bumps in the venturies and I know it came off an 84 Chevy van, it's non ccc. I know it's a Chevy carb and its got the inlet on the side but I don't care what it looks like I just need a good carb for my build. I want a street demon 750 but I can't afford it right now. If it helps, the van was an industrial type with a 350. I guess what I'm asking is will this carb run poor or will it be more than adequate? My build is a factory 70 olds 350 4bbl with 6cc dish pistons, uncut #6 heads and the only mods are the camshaft 496/520 lift, 300/310 duration or 224/234 @ 50 if you will, and adjustable roller rockers. Down the road id like to do a 7111 intake, st demon 750 and headers but for now I'm going to cap the crossover and run duels with no x or h pipe. I'd really appreciate advice from real quadrajet guys. I seriously think this carb will be a good runner but I don't want to find out the hard way. I've taken into account that it was rebuilt 20 sum years ago and never run, I might have to replace the accelerator pump. Thanks guys.

 

I don't know if I'm a "Quadrajet guy" but I've rebuilt plenty of them. I don't see why this wouldn't work for you. The Quadrajet is a good carburetor and as long as you set it up properly it won't overpower your engine the way a Holley with mechanical secondaries would. Just make sure you use a tach/dwell meter, timing light and vacuum gauge to tune your car and you will be happy.

As far as the 20 year rebuild goes, I would try to run it first without opening it up. It might weep a little bit of fuel but after the seals swell it might be good.

 

You may have issues with non compatible rubber parts. You already know that the fuel line needs to be modded and possibly the choke. Other than that it should work fine.

 

I have a Road Demon 750 that"s been setting on my shelf for 10 or so years. If I were going to use it, I would put a kit in it but it ran great when I was using it on a 455 engine.
I"ll sell it fairly cheep if you are interested.

 

Ok thanks guys. I was hesetent because awhile ago someone told me that carb being a mod quad wasn't the way to go but I always thought the mod quads were supposed to be good. I'm going to give it a try and we shall see how it performs.

 

It may need more fuel and air at idle with that cam.

 

If it was rebuilt 20 years ago it probably doesn't have a plunger that will tolerate ethanol.

 

If it runs at idle roughly, how would I modify it to alow more fuel and air? Also does anybody make an upgraded plunger for ethanol? For the qj at least?

 

Try this fellow. He is a member here as well.


https://www.googleadservices.com/pag...Q0QwIKQ&adurl=

 

Most any plunger you buy these days should be ethanol proof unless it has been on the shelf a long time. It seems to me the one I put in my 54 was blue. I don't know if this is common or not but most of the old ones were leather.