I have a Holly Dmimator 1050 that is flooding the engine - runs like hell at 3000 rpms but dies at idle. Had a friend rebuild it and same problem. Switched carbs and the running carb works on both motors fine. Seems like this carb is dumping toouch fuel. What am I missing? Thanks!

"mildthunder" has a ton of good input on carbs. but off the top of my head.. powervalve issue

Can you see it dumping fuel down the bowls?

Chk the float levels. If good I would agree to chk the pv's and make sure the diaphragm is good. Also chk fuel regulator/fuel pump.

clear the air bleeds on the top, mine runs like crap if they are not perfectly clean

A Holly 1050 is a stupid big carb designed for large cubes and high RPM's. What do you have this thing on? I would guess you are way over carbed.

.

Leaking or wrong power valves...if it even has them.
Dominators are designed for drag racing, to either idle or run wide open - nothing in between.
Not really the best carb for part throttle operation.

I Have 1050's on 496 strokers and they idle, cruise, and wot just fine. I mostly cruise at 3800rpms and they never miss a beat. Third season without touching them so the problem is not the carb size but not set up properly. How to set them up, that I don't know. Lol I pay someone to do all that.

10-4 on that.been there and done that.

All of that said, he still has a carb problem.
Like the other posters said, leaking needle valve, blocked air bleeds, or the wrong or blown power valve. ( if it has power valves).
Was it doing the same thing before it was overhauled?
Dominators are great carbs, but unless you are running an all out mega cube engine with an inch of cam, you will make more torque with an 850 and not lose much, if any, horsepower at upper rpm's.