My 67 Cutlass Supreme has a 330 high compression engine, looking to replace the Carb, Thinking of the Edelbrock 600 CFM/ Manual choke. Ran the numbers 330 ci and max RPM
of 5500 it comes up with 450 cfm?
Seems the 600 might be too much, What are you guys running with your 330's

Thanks Brian

 

I ran one on my 330 way back when. It ran fine with it. Note, you'll need a square to spread bore adapter.

 

Get a Street Demon 625, should bolt to your stock intake. Those calculators are way out to lunch, calculate way too small.

 

Hi,

I ran a Buick Carter AFB on mine 625cfm ran good, better than the original 4gc

Regards,
Jim

 

What's wrong with the original Qjet (which was 750 CFM, by the way)?

 

Ditto what Joe P said. I run a Q Jet on my 66 Cutlass 330 High Compression engine and it runs great. Engine was rebuilt with an upgraded camshaft and have no issues.

Wayne

 

For what you would pay for a new "universal application" carb, you can have one of the rebuilders (Cliff R., Everyday Perf., Sparky, just to name a few) rebuild your QJ better than new and dialed in to your particular specs!

 

Are there any issues with your current Qjet? If you are going for a basically stock refurbishment, use your current carb. If you want a boost in performance and an upgraded tune, a 76 to 80 800 cfm Qjet is a better starting point.

 

had lots of issues with original just want to start off fresh

 

Then don't go with the Edelbrock, the AFB and AVS has had that issue since the 60's on OEM vehicles. Edelbrock basically copied the Carter carbs. Get the Street Demon 625 with the Aerospace Polymer main body, probably pretty close for a factory high compression 330 out of the box.

 

Joe you said it has a 750 cfm carb, can you let me know your ref material so I can read and learn, thanks Brian

 

All Qjets are rated at 750 CFM until you get to the late-70s models that are rated at 800 CFM. The secondary air valve is tuned to the application to limit flow to what is required. For example, the Qjets on the Olds 307 motors have a stop that limits secondary air valve opening to only about 70 degrees vs. 90 deg on other models of the carb.

 

Starting off "fresh" doesn't mean you won't have issues that need to be resolved. Back in the 80s I put a Holley 600 on my car and went through a LOT of modifications and tuning that required purchasing additional parts to try to get it to run as well as the original QuadraJet. That carb didn't stay on very long, because it just didn't work as well as the QuadraJet. Since then my recommendation has always been to keep the QJet if at all possible.

 

^^^THIS. Don't kid yourself. Any aftermarket carb will be set up for a Chevy 350. You'll need to customize jetting, fab linkage, modify fuel lines, and connect the choke for it to work. That's not to say that you can't get good results with an aftermarket carb, but don't think you're just going to bolt it on and go.

 

Thanks guys, alot of good info, I will now keep the old carb on the shelf, if the new one goes bad, Thanks Brian

 

35tac/ Wayne thanks for helping, you mentioned a cam upgrade, what are the specs? Thanks Brian

 

What new one did you go with?

 

My Vista had a Edelbrock carb on it when I bought the car, I just didnt like the way it ran and with the adapter the air cleaner rubbed a hole in the hood insulation. I tried a Holley VS 750 on the car that I already had, still didnt like it. A friend gave me a Q-jet that he had sitting around so I sent it to a guy in Arizona to get rebuilt. When I put that Q-jet on the car it was like a totally different car, I didnt have to adjust anything and it runs great. Turned out the carb was originally on a late 70s Cadillac.
I paid $175 for the rebuild and $25.00 shipping.