Heavy car carb advice wanted

[ewo357]

I don't know about the QFT's, never ran one, but on EVERY new or used Holley carb I use or mess with, I check the flatness of the main body. They are almost always warped, even from the factory, and it will give you problems sooner or later. True it up with a file and it'll give you much better service. Sometimes they're so bad I've had to use 40 or 60 grit sandpaper over a file, then finish it off with just the file to get rid of the sandpaper scratches. It seems ridiculous to have to do this stuff on a new part, and it is, but it can save you some headaches and chasing your tail trying to find a problem.

What do you think of the Holley ULTRA street avenger? They have an aluminum base that is supposed to be flatter. I don't like the half shiny, half colored look of them (I like the old school gold look) but it will be under the air cleaner. I see they have a 770 cfm that is in the size range everyone is recommending.
Thoughts...?

[Joe-JDC]

It is one of their Pro Series, and the calibrations are excellent out of the box.  Contoured body, notched floats, jet extensions, four corner idle system, reusable gaskets, power valve blow out protection, etc.  I have seen this carburetor perform on many dyno test comparisons, and it always comes out on top of the other regular Holleys.  It is within a few hp of a dominator on the engines I have witnessed it installed on.  Just my opinion, but it flat works.  Joe-JDC

[FElony]

Seems many people have forgotten the "discovery" years back that the Avenger series was rated under different flow conditions than the traditional Holleys, and you should essentially yank the last 70+ or so cfm off them to compare apples to apples. Thus, an 870 SA would be more in line with the 750/780 standard Holleys.

I have little doubt that the carb Joe (aka The Duke of Windsor) recommends is kool, but at some point you are splitting hairs against the thickness of your wallet, and then again versus the amount of miles this car will see. I am presently stitching up a voodoo doll to force you into dual 600's. I hope you are really ticklish.

[nhsohc]

If you have any experience with a Thermoquad, try one of the old Superquads they sold in the '80s.  Can't be beat for a heavy car.  On e-bay all the time.  Mopars in NHRA stock classes cleaned up using these.  And will get great mileage if you stay out of the secondary's.  Just another option.

[e philpott]

Holley 80529-1 750 cfm vacuum secondaries, down-leg boosters work extremely well on just about anything you want to put it on.  Summit HLY-0-80529-1 $639.95.  Joe-JDC

^^^^^^^ very good carb , worth the extra money and you get what you pay for !! ^^^^^^

.... the 3310's we all love are the older ones and a little tougher to find these days but rewarding when you do  , the new 3310's are not as nice my in my opinion

[ewo357]

Well, I picked up a couple of older 3310s. One is a -1 and one is a -3. Any tips for when I rebuild them?

[FElony]

Well, I picked up a couple of older 3310s. One is a -1 and one is a -3. Any tips for when I rebuild them?

The -1 is downleg booster, and the -3 is straight leg. Look closely. The -1 is more desirable.

[ScotiaFE]

Well, I picked up a couple of older 3310s. One is a -1 and one is a -3. Any tips for when I rebuild them?

Get a big table and put a clean white table cloth on it.
Take it all a part and place each part like the exploded view.
Clean and put back together and adjust it on the table.
Bag it.

Those Holley SA carbs, I ran the big of the box for years on a 390
and I can't ever remembering even putting a screw driver on in all the years I ran it.