My guess is, in addition to the leaking gasket, he was trying to tune the motor to correct a problem that had nothing to do with the carb....... the valve springs.
What carb are you running anyway?
Since it sounds like it’s had the bowls off a bunch of times, I’d just put a kit in it.
The gaskets on Holley style carbs are an intergral part of how they function, and can result in erratic operation of the carb when they’re compromised.
Best to just replace them.
Carb kits are cheap.
It’s amazing how quickly new parts can be turned into junk when they’re not properly matched.
