How to find a vacuum leak

How do you find a possible vacuum leak around the intake? It’s a Drag car only.

Oreillys brake parts cleaner with the straw on it,spray a little at a time around ports,carb base. If it sucks in the cleaner rpms will increase.

Just make sure it's the flammable kind... some of the cans say it isn't.
I like an UNLIT propane torch for this, or a careful squirt of carb cleaner that is definitely combustible

Smoke Test it with a smoke machine...

This is all I do.. just make sure its flammable... simple and cheap

Spraying stuff may or may not find a leak between the intake and head

^^^ yes it may have a leak on the bottom side of the intake & I would think it'd be more likely to happen there than above cuz of the heat/agitation. I'v e thought about introducing it under the valley pan (BB) or under the intake (SB) but that might be dangerous with adding that much flammable agent. EDIT & up top be sure to shield the side of the carbwith a piece of cardboard or paper so the spray dont get sucked into the carb & give you a false positive

Just grab a 2 to 3 foot length of old heater or garden hose, one end to ear, the other to possible leak area. You can tell! Makes a good stethoscope as well.

I've had the best luck using water. Get it idling, warm it up, and spray any suspect areas.
The idle slows down when it sucks in even a small amount of water.

HMM Good idea I'll try it next time. Part of the issue with brake / carb clean is its flammability on a hot motor. In addition when it evaporates it richens the surrounding air which can lead to one chasing their tail

This gets my vote. No mess, Nothing to catch fire. The engine will pick up speed as soon as it sucks in the propane.