Cliff's Quadrajet Parts and Rebuild Kits

Is this new base gasket going to be OK to re-seal if pull the carburetor back off to reset the float??

Its a 4x4 truck, gotta stand on a step stool and then lay across the radiator and front of the truck to work on the carb. PITA

 It's been my experience that if the gasket isn't too old or been crushed from over-tightening then it'll be fine. I've installed and removed my carburetor multiple times while tuning it.

 Rick

"Newly rebuilt"?

Who did the rebuild and exactly what was done to it?

Engine specs, compression ratio, cam card, etc?

What distributor and what has been done to it (how much timing does it add with the mechanical curve and VA)?

Tuning goes far beyond simply adjusting the APT screw.  You have to have the distributor working correctly and adding the right amount of timing as well.

The carburetors idle system must be set up for the engine, plus the right jets and metering, PP spring, etc.....

Is this new base gasket going to be OK to re-seal if pull the carburetor back off to reset the float??

Its a 4x4 truck, gotta stand on a step stool and then lay across the radiator and front of the truck to work on the carb. PITA

No increased rpm at "tip in test" with APT seated indicates a too rich mixture.

A too high float setting (too early delivery of fuel to the circuits makes a too rich mixture) and you may loose control of the APT adjustment.
Also too high fuel pressure will make the fuel level too high (same result, rich mixture).

No increased rpm with APT seated indicates a too rich mixture.

It is NOT a good idea to set the float at the same setting in different makes of the Quadrajet since the brass inserts in the center nozzle are different size in nearly every make, Buick, Cadillac, Chevy, Olds, and Pontiac all have their own nozzle sizes to start fuel delivery to the circuits depending on the demand from their engines.
Then you´ll have to calculate jetting depending on air bleed sizes.

As i said, ALL calibration starts with the float setting for the make of the carb that´s a candidate for a certain engine.

If correct float setting does not help, use a smaller main jet OR a larger primary rod to have the desired result.

"One size simply does not fit all, try walk a mile in your spouse's shoes."

A couple more degrees of timing might fix it.