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Carb recommendations for a 383 stroker???

blowedupmotor87

blowedupmotor87

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My K3o has a 383 stroker with what appears to be a GM performance high-rise Quadrajet style intake. The day I bought it, it had a Holley 750 double pumper with a manual choke and mechanical secondaries. That carb was leaking like a sieve, the previous owner said he would get it rebuilt for me for free since he had said it was a running truck. (six months ago... I doubt I will ever see the carb again, he wont return calls or texts) I highly doubt the 750 double pumper would have been a good offroad carb anyway but, would be nice to have it now to get the truck running and then sell the carb later!!!!

So.... that leaves me with no carb and a lawn ornament for a truck! I need a carb pronto as my HOA has given me until february 1st to register my truck or remove it from my driveway before they fine me.

What would y'all recommend??? I am guessing it needs to be 750CFM since it (supposedly) ran great with the Holley double pumper. It is purported to be a 383 stroker from an asphalt late model race car so I would assume it has fairly high compression (compression test was 220psi on 6/8 of the cylinders, one was low (110psi), one was very low (50psi) so, the motor will need to be pulled and rebuilt but, I need to get it running long enough to inspect and register so it can continue to sit in the driveway), it also likely has a fairly aggressive cam.

I'd like to go EFI but, that is not in the budget nor do I suspect I would be able to work the kinks out of an EFI swap in such short time. So, the focus now is on what carb to run!

I am thinking about this one, the question I have though is- why does it say up to '85? Is '86 different somehow??? Also, does it even matter since the motor isn't original to the truck anyway???

http://www.summitracing.com/parts/sum-210214/overview/

Any thoughts and advice would be greatly appreciated, I know basically zero about carbs!
 
If you just need it to pass inspection and move on it's own for now, I don't think I'd spend that kind of money on a new carb.

Find a used Q-jet, throw it on there, pass inspection, save the ~$250 from the avoided cost of a new carb, and invest it into EFI once it's inspected.

I'd be surprised if someone on here wouldn't sell you a used Q-jet they know works for $50-100.

I say Q-jet, but realistically, no reason not to go Holley or Edelbrock since your criteria are "truck must move". Q-jet is the best all around carb you are going to find, but I wouldn't pay a premium for one. I'd get the first thing you can find for the best price. 500, 600, who cares? Two near-dead cylinders, the motor isn't what it should be anyway.
 
Here's a link to Hotrod magazine article that can help determine the size carburetor you need:

http://www.hotrod.com/how-to/engine/1408-how-big-a-carb-do-you-need/

With that you can decide what size carb to get.
From my experience I like the Edelbrock Thumder Series for off-road.
It has easy adjustments and simple to rebuild. The spring loaded needle seats help prevent stalling out on steep inclines.

I had a Holly before, it worked good on the street but kept stalling out on the trail.
 
After hemming and hawing for a while, In went ahead and ordered the carb from the link, we'll see how it goes! Also ordered an electric choke conversion for it, some Hedman 69230 headers, and Stage 8 header bolts!
 
blowedupmotor87 said:
After hemming and hawing for a while, In went ahead and ordered the carb from the link, we'll see how it goes! Also ordered an electric choke conversion for it, some Hedman 69230 headers, and Stage 8 header bolts!
Click to expand...
Are you going to keep the headers open for a while as a thank you to the HOA? :D
 
I think the 86 up q-jets were computer controlled or had some kind of electronic b.s. on them.

Here's everything you need to know and then some about the venerable q-jet. click me
 
Got a vacuum secondary 770 street avenger on my 383. Plenty of carb, Prob even a bit on the big side.
 
RobTav63- about tempted to, LOL!!!

Big Ray- I do believe you are correct about the computer controlled carb. That is LOOOONG gone from the truck though. Had a Holley 750 double pumper with manual choke and mechanical secondaries when I bought it. Carb was leaking like a sieve, took it off and P.O. said he would get it rebuilt for me (free).... it has been like 6 months, dude won't return calls or texts so.... looks like that's a lost cause. (never going to get that Holley back it would seem)

Bowtie85- how have you liked that carb offroad?

pblaze725- thanks for the info and the link!

dyeager535- I don't think I'll ever actually end up switching it to EFI (though I wish I could) so, the carb I pick now will likely be on the truck the whole time I own it so, want to do it once and (hopefully) do it right! I think I am going to run the engin e as is for a little while (just to enjoy having the truck running for a little while) but, I will be pulling the engine and rebuilding it.
 
There is a simple formula to get correct carb size.
Cubic inch (X) max RPM (/) 3456
So let's say you spin your 383 to 5500, that puts you at 609 cfm. Most engines need carbs much smaller than their owners think. A bigger carb will open up a few hp on the top end, but at the expense of response and torque down low, where a truck needs it. Smaller is almost always better than bigger. I wouldn't go over a 650.
All that being said, I hear good things about the Holley Truck Avenger.
 
I'll take a good built q- jet over a truck avenger or carter avs any day of the weak. They might be harder to change metering rods and set the float level ,but once you do it a couple of times ,it 'll be like second nature.When you install the carb, don't over tighten or you will warp the top plate,and it will leak fuel .Also,Idon't know why Summit advertises a q-jet for 305-454 cid engines-yes it's the same carb, but the float height and jets/metering rods are different for all 3 engines.summit should specify what the carb is set up for ,305/350/454.I wonder if the idle bleed screws have the plugs in them like the factory had, making them non adjustable?If they are plugged, it should be easy to take the plugs out., they probably aint plugged, though.The q- jet in my opinion gets better fuel mileage than a carter or holley, as long as it's set up right .The corvette website posted above by big Ray is excellent.I also like cliff's high performance forum , look it up. Cliff Ruggles is the author of a very informative book,and also offers a rebuild service and modifies them to work on any small block (within reason)and also offers hard to find parts . I'm going to order his book.Now I like a holley for all out racing, every body knows holley double pumpers and Dominator carbs are the best .My brother has a 67 rs/ss camaro with 402 baby rat engine,muncie 4speed and a dana 60 rear end with a spool and 4.88 gears, his carb is a Holley 850 double pumper with mechanical secondaries, and let me tell you that thing screams! Some dude with a cobra junk mustang was talkin shit with his big bad 428 , and I bet we beat him by three car lengths! Any way the q-jet is good for 4x4 aplications / gets better fuel mileage and runs better than holleys or carter avs at steep angles without sputtering and dying. But Holley wins in a street /race application or probably a mud racer. My q-jet does good on all but the steepest incline, and now I have found out that I can extend the vent tubes and install a spring loaded needle and seat(thanks big ray)The holley truck avenger is probably just as good or better than a q-jet you would think, but Ihave heard other wise.fuel mileage is won hands down by the q-jet cause the small primaries,just don't get into the secondaries!The Edelbrock(carter) avs gets the worst gas mileage of the three,and I am just not abig fan.No chevy engine came with those,well the 409,but for the most part those are for mopars. Any way this is my opinion.CHEVY RULES!!
 
I used a 670 cfm truck avenger when I put the lt1 in my 86. It did everything Holley said it would
 
I've ran a 670 street avenger on my 83 since I've owned it. Works pretty good on angles I'd say.
 
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