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View Full Version : Best Model Quadrajet for ZZ4 based motor



JMarsa
04-12-2005, 12:21 PM
I've got a ZZ4 (350/350 for those not aquaited) that I'm planning on adding a hot cam kit and bigger heads to get around 430 crank HP. I want to run a qjet but I don't know what different CFM they came in and what applications to look for that can support my HP requirement. Can a XXX CFM model from a 396 be made to run like the same XXX CFM on sat a Cad 472? I'm guessing I need to look for a 700-750 CFM model.

--JMarsa

68BNUT
04-13-2005, 06:20 AM
I beleive Qjets only came in two sizes 500 and 800. The way they work they only put enough in that the car needs. Of course you can get a Qjet from Jet performance that will be set up for HIGHER horsepower.

indyjps
04-13-2005, 03:48 PM
never got into performance q-jets, just ran a couple on drivers because of reliability. might look at pre smog big blocks, pontiac used quite a few of them. knew a guy running one on a 455 buick low 11's very consistent bracket car. he switched over to one after trying many holleys and after dialed in the car would run dead on numbers week after week.

justanova
04-13-2005, 08:01 PM
My dad put a Qjet from jet performance on his 402 in his 70 caprice and the carb works awesome. The jet guys will ask some specifics about your eng. and they will modify to suit your needs...and the price wasn't bad either.

4MuscleMachines
04-13-2005, 08:42 PM
www.jetchip.com (http://www.jetchip.com/) , they offer a nice carb...had one on my 72 455HO TA and it was the best bolt on for the money. Save yourself alot of headaches and wasted time in trying to tune your old carb. The extra cash for the jetchip is really less than what you will ultimately put into your old carb.

sporter
04-16-2005, 06:01 AM
Qjets came in either 750 or 800 cfm. If you remove the choke plate and shaft you'll pickup another 40 cfm. Since the Qjet is a vacuum secondary and will only feed the engine what it needs, you can't really go to big. GM put the 800cfm models on Pontiac 301s, Chevy 305s and Olds 307s. BTW, I've heard more bad than good about Jet Qjets but I believe its due to them being setup primarily for SBC vs BBC, Pontiac, Buick, etc. Most of the bigger engines need bigger idle circuits than most of the factory Qjets came with. You'll probably be fine. If you already have a Qjet, send it to JET and they will modify it for less $ than buying one outright. I had a custom 840 cfm Qjet built for my 455 by Cliff Ruggles for $350 with APT and it screams. Several other Qjet gurus out there to choose from. The beauty of the custom models is it will work for your combo right out of the box.

BRIAN
04-16-2005, 09:04 PM
Listen to the above that JET carb is got to be the best deal for the money out there. If the performance doesn't impress you the look of it sure will. The adjustable off idle makes tuning a breeze. HIGHLY RECOMMENDED. Under $400 through Jegs or Summit

JMarsa
04-17-2005, 05:53 AM
Thanks for the info. I've checked out their site. As soon as I settle on a cam I'll have them build me a custom unit.

--JMarsa

justanova
04-17-2005, 06:58 PM
Under $400 through Jegs or Summit

I'd recommend getting it straight from jet, because they will build it for your motor....the ones from summit/jegs are setup for common builds and may not be best for your application.

just my .02

skybu
04-19-2005, 06:19 AM
I had been thinking about this also. Has anyone tried the Edelbrock Performer RPM quadrajet ?