Best way to find an exhaust manifold leak?

[jabborabbo]

So I rebuild the carb and the old ‘67 runs like new...then the nasty click noise starts...it’s kinda loud when I first crank the truck, then it goes away when the engine warms up except it comes back when I accelerate, so I assume it’s a manifold leak, and I’m dreading what the fix may entail since the manifold has never been removed...so what’s the best way (or various good ways) to locate it?