which carb. should I get? here are my specs

[jpcamaro69]

I have a chevy 350. It has been bored 60 over. It has camel hump heads(I don't know the exact specs for them), I have a cam with 420/442 lift and a duration of 204/214, I have performer intake, Hocker comp. headers, 3" pipes and 3" ProFlows. I need a good carburetor for this engine. please help.

[MrPbody]

Holley 3310. Might be a little on the big side, but as it has vacuum secondaries, everything will work out... readily available and relatively cheap.

[jpcamaro69]

Where can I find a good one for a good price?

[MrPbody]

Summit, Jeg's, other Holley dealers. Avoid old carbs that need rebuiding, unless you're proficient in such an area. If you DO get an old one, get a book that describes the proceedure and tuning. Never use ANYTHING other than a true Holley kit for a Holley carb. If it doesn't say "Holley" on the outside of the box, as a brand name, it is not a Holley kit.

[jpcamaro69]

I found a Holley 750 double pumper race carb. #4779 for a good price. Is it to much for my engine?

[1977moneypit]

Just remember...bigger is not always better as far as cams and carbs ar concerned. Unless it is a spreadbore carb (smaller primaries and larger secondaries). Usually what happens is someone gets a HUGE carburetor and it just drowns out there motor due to too much fuel. Actually if you have a little smaller carb you will have a much more "touchy" gas pedal. You will get better responce and sometimes better gas mileage...
LEAN=MEAN...RICH=B***H

[calgary_redneck]

q-jet

[MrPbody]

If you have the dual pattern Performer, I tend to agree with Calgary Redneck. Q-Jet is perhaps, the best carb ever made by anyone. I know, I know... "Quadra-Junk". Only in the hands of someone not skilled in rebuilding a complex carb! Send it off the Cliff's Q-Jets in Ohio, and see what magic he can work! Many a 10-second Pontiac-powered Pontiac out there with a Q-Jet on it.
But if you have the Performer with only the Holley flange, I would feel you lose more by an adapter, than you would gain by the good design.

[Triplet]

~600 cfm vacuum secondary Holley or Demon. I'm sure that Edelbrock or Quadrajet or Carter of the same size and vacuum secondary would work fine too, but I like the Holley style carb for ease of tuning and they've done great for me. Definitely stay away from that 750 cfm carb you found, way too big and it won't want to work well with a cam that small. Contrary to what was said above, a bigger carb on a smaller engine will tend to run LEAN, since the air going through your venturi is moving too slow to pick up and then atomize the fuel, so you don't get enough fuel. A rich engine is ok, as long as you aren't washing down the cylinder walls with fuel! A lean engine can be very BAD! You can burn holes in valves, burn pistons, all sorts of awfull things!

Stick with a 600 cfm MAX, you could even go smaller if you wanted.

Let us know what you do and how it runs!

[MrPbody]

Circle tracker's rule of thumb: "Lean is mean, but fat's where it's at!"

Yes, running the mixture lean will produce more power, until... You reach the point where the cylinder can't get cool because it's TOO lean. Running a tad rich may use a bit more fuel, and it may cost you one or two horsepower. It will not, however, damage your engine the way too lean can. Running TOO rich (black smoke coming out at speed) will wash the walls as previously mentioned (the raw gas breaks up the oil film on the cylinder wall). That will lead to premature ring failure and/or galling of the piston.
Any vacuum secondary carb will be "self-regulating" when it comes to volume. We've found the Q-Jet and genuine Carters to be better than the others. Lots of reports of tuning problems with Edelbrocks (Carter clones).

[NOVA71]

Just wondering if you got a carb yet? If not I can tell you what I know. My friend bought a "BRAND NEW" Edelbrock (carter style) carb and could not get it to work like it should on his 350. I do like the Quadrajets. They are usually the best compramise you can get for good performance and fuel milage. I decided to buy a "BRAND NEW" Holley model 4175 for my Nova. It was a spreadbore style that worked great right out of the box. Ran a bit rich but no big deal. The electric choke was amazing. One pump, turn the key and drive away. It was like I had fuel injection. After a few years I decided another upgrade was in order and this time I picked up a used (but like new) Speed Demon 650 vaccuum secondary and electric choke. I've only driven the car once with this carb on it and this is definately the carb I'm going to stick with. It really pulls hard with this carb. Although I haven't had the electric choke hooked up so I can't say how well the choke will work. I would definately recommend a 650 Speed Demon. I'd say you probably wouldn't want anything bigger than a 650 and vaccuum secondaries are great for the street. Good luck!

[curtis73]

Absolutely, hands down, Qjet. No other carb can provide a more consistent and progressive fuel deliver curve than a Qjet. The single best designed carb ever if you ask me. People think they're no good because they buy an ancient vehicle with 200k on them and wonder why there is a bog at full throttle. If they only knew that all it took was a tiny adjustment with an allen wrench, they might be a lot happier.

Better mileage, vacuum operated secondary metering, a truly CFM-on-demand carb that can't be beat. The bottom line is that if you present that engine with more than about 600 CFMs, it will be too much and you'll lose power. With a 750 or 800 Qjet, it will only open the secondaries enough to let 600 through. Remember, this exact same carb architecture was used on everything GM made for a few decades; everything from Caddy 500s, to 140-hp Olds 307s, and back to 450-hp Buick 455s... and did it all while passing EPA requirements up to 1988.

A close second would be an Edelbrock 1406. 600 cfms, fair to good mileage, easy to tune on the car, and dead nuts reliable.

[cowood]

I Have To Agree W/ The Nova Guy Definite Ly A 650. Any Thing Bigger Will Be Pissing In The Wind.

THE PROBLEM W/ Q-BOGS IS THEIR SPECIFICALLY TUNED FOR STOCK ENGINES . CAM &INTAKE UPGRADES UPSET THE TUNING ,IT TAKES A FAIRLY EXPERIANCED CARB GUY TO TWEAK THEM. A HOLLEY ,B/G, OR EVEN EDL. ARE MUCH MORE FORGIVING.

[79Bandit]

you dont want a holley 750 i have it on my 79 trans am with a 400ci out of a 68 bonneville and its to big..the car runs great but on take of you have to pat the gas to get going. but once your going your gone

but another thing is its just running of 2 of the 4 barrels cause the car doesnt have the power the carb wants for the other 2 to kick in...