Ok So I have Holley 1850s on top of a preformer rpm intake manifold. I can bring my car down to proper idle rpm with out it dying. The vacuum is fluctuating from 17-10. I can tell there is a leak around the intake, the vacuum advance works, the brake booster is holding vacuum as well. Idk what to do?? Need help!

 

have you lifted the carb up to make sure the gasket is sealing right.

 

If there is a leak around the intake (Upper i'm assuming) Like crabs said, I would check the gasket, vacuum shouldn't matter at this point if all the valves a hoses are sealed correctly

 

You need to replace your leaking carburetor base gasket (between the carb and intake). Did you use an adapter plate of any kind?

 

No adapter plate, it didnt have one on it before I pulled the carb off.

And I'm sorry I ment to put I think there is a leak around the intake. It's my last guest on what's going on. And I think the carb was sealed fine. Has a brand new gasket on it.