hjgator

I'm looking for a new carb, the two I will chose from Edelbrock 650 thunder avs or the Summit racing 600 cfm, can anybody give practical advice on this. you know the one summit recommends. thanks, hjgator P.S. it's a 79 Corvette zz4 with a 350 turbo, Hooker super comp headers only raced once a year.

ZZ71S

I am pretty sure the zz4 turn key comes with a Holley 770 street avenger.
I bought the 770 with no tuning it runs very good

hjgator

My zz4 is 7 years old it has a quadrajet on it now which has been giving me trouble, the previous owner did not get it with the carb. Summit said the 770 is to much carb for the 350 turbo

ZZ71S

You know I think GM used a Holley 750 to get the 355 hp and 405 torque.

spedaleden

I have a fast burn GM crate motor. This motor comes with a Holley 750. I had an Edlebrock on it and it was terrible. I'm not saying Edlebrock is bad. I just thought it was much more difficult to set up than a Holley.

Your ZZ4 has less horsepower then my set up and I agree that a 650 should work fine with your motor enenthough I don't know all the peramiters of your motor. I would go with a Holley 650 with vacuum secondaries or repair what you have on it. Q jets are very nice carbs when set up.


Just my 2 cents

cowjazz

I hate to muddy the water with a carb you did not suggest, but here I go...Barry Grant makes one for the ZZ4 engine:

http://www.jegs.com/i/Barry+Grant/13...VCZZ4/10002/-1

MN80Vette

Bigger (cfm) is not always better for carbs. I recommend the carb selection tool at the Holley web site. Look for "What carb do I need?" in the upper right corner of any page.

I have a GM 350 HO (330 hp, 380 lb.-ft., 64 cc iron Vortec heads, 212/222, ,435/.460, 9.1:1) - a little milder than your ZZ4. I stepped through the choices - vacuum secondary, electric choke, street use, etc. The top 3 recommended carbs for the 350 HO are the 600 cfm 80457S (that's what I have), the 650 80555C (Q-Jet carburetor replacement), and the 670 cfm 80670.

As the Holley site says, "It is important to remember that smaller CFM carburetors will provide better low-end throttle response while higher CFM carburetors will deliver high rpm power."

69vettester

I would Put the Holley 670 street avenger on the ZZ4.
I have a Speed Demon 750 on my 383 that is built off the ZZ383 shortblock.

kyeakel

I have a 78 with the ZZ4. Had an Edlebrock 750 on it at first. It ran like crap. I've put a rebuilt quadrajet on it now, runs much better. I've heard quality issues with the Barry Grant stuff, no personal experience though.

Kipp

tnovot

I have a Holley Street Avenger 670 CFM on my 355 HP ZZ4 and I really like it. It starts easily, pulls smoothly and strong through the gears, and has no bogging or noticeable lean condition at any RPM.
Terry

hjgator

Thanks for all your input guys, I have decided on the Holley Street Avenger 670. Ordered it from Summit today, thanks again, hjgator

Dantana

I've got the 670 street avenger on my ZZ4 set up and it works very well. I don't think I would go any bigger unless you ditch the automatic. I'm running pretty much the exact set up you are by the way - ZZ4, Hookers, TH350, .373 gear...

FKING1

You will be happy with this choice. I run Holley 670 Street Avenger (recommended by Summit) on my ZZ4. If you get a stumble under quick acceleration there is a fix on this site. Do a search. Either accel cam off location or bigger jets. I went to bigger jets on mine and it runs like a bomb.

3JsVette

I have an Edelbrock 750 electric choke on a ZZ3 in my '55 Nomad with a TM350 trans and a 3:08 rear with a 27.5" tall rear tire. The carb has been on there 10 years and the car runs great and gets almost 18 MPG