While the carb spray trick is a good one, it is sometimes hard to tell where the leaks are as the stuff gets everywhere for the engine to ingest.
A more specific test is to take your car to your indy and have him pump inert white gas into the engine and see where it leaks. The $ spent for one hour of labor can save you lots of $ on replacing the wrong parts.
Mine leaked at the injector holders, plenum and intake manifold gaskets, and the fix, if somewhat laborious, is here
, and resulted in the smoothest idling 380 ever. Your engine is similar.