ZZ 383 Info
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 895
Likes: 4
From: whitman massachusetts
ZZ 383 Info
I was hoping some members who are running a GMPP ZZ383, might let me know what they selected to run for a carburetor on their engine, and if they are happy with their choice. It is going in a 1971 roadster, turbo 400 automatic, 3:36 rear end gears( which I believe was the performance option for turbo 400 tranny). Engine is running what was recommended from GMPP, so in staying on that basis, am looking at 750 CFM choices. Not sure on brand names, and also mechanical or vacuum secondaries. Any info is appreciated.
Instructor
Joined: May 2008
Posts: 153
Likes: 0
I'm running a edelbrock 750 vac. sec. elec. choke. Carb preferences are like asking, whats your favorite meal? I'm happy with it now, but it seem's like there's always something better out there! You will probably need a tuning kit....
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 895
Likes: 4
From: whitman massachusetts
carbs
Thanks for the reply. I am more concerned with a ZZ383 owners LEAST favorite meal. I can't afford to make an error with this carb purchase, so if a ZZ owner says he tried the Edelbrock #1407, but jets and metering rods were not enough for the engine so had to move up to the #1406 to take advantage of engines potential, it might save me from making that same costly mistake. I know that most all the carb makers still in business, make good products. Just hoping to get some product review from someone who is actually using a specific carb set-up.
Peace
Burning Brakes
Joined: Dec 2003
Posts: 1,004
Likes: 7
From: Adelaide South Australia
Just my experience...... for real world feedback.
I had issues with the Edelbrock 1813 (Thunder series AVS, 800cfm) which was supplied with my turnkey crate 383.
Could not eliminate an off idle hesitation, and it would stall (cough) on U-turns and any fast left-right switchbacks. Spent several hours on the dyno with variety of factory rods and jets, but could NOT tame it.
Swapped it with a Holley HP Street 750 (dp) and gained 15hp at top end, but lost out about 15hp below 4000 rpm
But it now runs good without any issues.... except for cold starts
Maybe it was an issue with the low vacuum, roughish idle of my cam, but I gave the carb to a mate with a 390 bb 65 Thunderbird, and it works perfect in his application.
willem, as you have an auto trans, a vacuum secondary carb is probably a better choice for your setup....
I had issues with the Edelbrock 1813 (Thunder series AVS, 800cfm) which was supplied with my turnkey crate 383.
Could not eliminate an off idle hesitation, and it would stall (cough) on U-turns and any fast left-right switchbacks. Spent several hours on the dyno with variety of factory rods and jets, but could NOT tame it.
Swapped it with a Holley HP Street 750 (dp) and gained 15hp at top end, but lost out about 15hp below 4000 rpm
But it now runs good without any issues.... except for cold starts
Maybe it was an issue with the low vacuum, roughish idle of my cam, but I gave the carb to a mate with a 390 bb 65 Thunderbird, and it works perfect in his application.
willem, as you have an auto trans, a vacuum secondary carb is probably a better choice for your setup....
Last edited by OzzyTom; Feb 1, 2009 at 07:26 PM.
Pro
Joined: Mar 2008
Posts: 716
Likes: 1
From: Albuquerque New Mexico
I've been running a 670 Avenger on my 383 that's in my '68 Camaro. It runs great - very crisp. This is a fun wknd. car that goes to drag stirp several times a year. Had to re-jet it (for higher altitude) and put in a lighter secondaries spring and it works very nice. I also have a 750cfm vac. secondary holley carb that I'm going to try on it to see what happens - I know that's what GM & Holley both recommend. I'm guessing I'll gain a little at 5,500+ rpm but probably sacrifice lower RPM crispness and power. In my case the ZZ383 really needs a 700-750cfm double pumper has 5spd. & 3.73s. I would think you would be good w/a 750 cfm vac. secondary holley.
Last edited by WillEE; Feb 2, 2009 at 03:47 PM.
Pro
Joined: Mar 2008
Posts: 716
Likes: 1
From: Albuquerque New Mexico
p.s. vac secondary carbs allow for less of secondary fuel supply jolt to the engine which in cases of auto trannys provides a better reaction/adjustment period. Mech. Secondaries have a 2nd accelartor pump dedicated to the rear barrels which as I understand can be too much for cars w/hi-way ratio style gears and auto trannys. These cars need a more subtle transition is my understanding but maybe someone else can provide more detail.
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