Tonytz06

What is a good carburetor replacement for the quadrajet that came on a 427 390HP? I don't have the original so I am thinking of a Holley?

Thanks;

Tony

427SIXPACK

Is it an original car ? do you want to keep it original ? I might be able to help you with one if you want to go that way with a "FACTORY" rebuilt one..............whats the date code ?.

Vette5.5

Personally I like Quadrajet's, as once you learn how to tune and maintain them, there's really nothing better. You've got to realize that anything over 40 year's old is going to need some attention to keep it functioning properly. I'm running a well set up Quadrajet on a strongly built Old's big block car, and thottle response is second to none. Edelbrock seem's to agree, as it's the design they're using.

72ls5fla

Tony,

I'm 99% sure that if you use a Holley QJ replacement - there will be modifications needed to the air cleaner base (by the elbow) to clear the secondary accelerator pump. If you use the vacuum secondary replacement, there will clearance issues with the rear vacuum dashpot.

This will hold true for open or closed air cleaners. The aircleaner elbow sits to low and needs to be raised up about 5/8 -> 3/4 of an inch or so. Since yiur car is BB car, clearance should not be an issue.

The best solution with the least amount of grief is to put a new QJ on the car.

Now I personally like Holley carbs. Once they are setup and tuned right - they kick the crap out a QJ.......
But from a easy replacement standpoint, QJ is the way to go.

Ironcross

the advice I can submit is to find any parts store that handles 'Tomco rebuilt carbs. They will be one of the best to find a matching carb for you.....You can check them out on line by typing the name in the browser and also ask for the nearest supplier to you....

Tonytz06

I agree, nothing wrong with a quadrajet. In my case, the original carb was long gone when I got the car. It had a Holley on it when I got it.
With the exception of the carb. the car is original.

427SIXPACK

are you interested in a restored factory original carb ? what date do you need ?

Tonytz06

Ok, thanks again for the feedback.

BBCorv70

Don't mean to hijack this thread. I'm having a lot of grief with my QJet.
Originally a QJet rebuilt by Holley, POS. I just had it 'restored', looks nice but still has issues. The rebulder replaced the main body, the one I had was butchered by Holley.. I am getting close to chucking it into the trash can and buying a Holley 4175 if my QJet cannot be fixed. I may consider buying another IF I can trust it will work properly.

Does your source have a carb for a 70 - 454? Needn't be date code correct, just appropriate for the car. If they do, any idea how much?

427SIXPACK

send me a PM of exactly what your looking for ?

Faster Rat

My local vette shop found me a brand new Q-Jet, still in the plastic tray with yellowed old shrink wrap. The number stamped on the air horn is 17054917 and the date code is 0206, so it is either from 1976 or 1986. There was a different number on the box, which Joe Lucia on the NCRS board told me was more important. I paid $722 for it and $28 freight. It is supposedly a replacement carb for an early 454, not my 427. Probably works on truck engines as well. All I had to do was replace the cup on the accelerator pump. So far I have not messed with jets or metering rods. No rebuilt carb can compare to a new one, so if you are interested I will find out where it was purchased.

I was looking at $1300-$1400 for a restored correct and dated Q-jet. Decided it was more important to have a good running carb for my driver quality car.

TheycallmeDave

A DEMON Carb...hands down ---- A Speed Demon if you need a choke or a Mighty Demon if you dont. If you want maximum low end torque like you wont believe...then get ANNULAR boosters on it , not downleg (one published report from a Magazine proved on the dyno that Annular Boosters were good for an additional whopping 90 ft. lbs. of torque . I can attest to it on my 1970 468 cid) . Carb comes close right out of the box for high performance street use. Contact Demon Carb for what size to get for your particular setup. (im assuming you dont care about originality and want max. performance) .

BBCorv70

Thanks for the offer. I talked to the fellow who restored my carb, said he'll have another look. I'm going to send it back, see if he can make it right before giving up and buying another. I'll get back to you if I find I need to buy another carb.