SOLVED! 318 2500-3000 rpm idling issue. Don't think its a regular vacuum leak. Swapped 2 intakes, 2 carbs ,and 6 different gaskets still no luck.

As I said earlier in this thread....but the message is not getting through.....
A high idle rpm of 2500+ rpm is because the engine is getting air from somewhere.
High idle rpm is NOT because of:
- ign timing problem
- other ign [ coil, plugs, etc ].
- valve train
Reason is that any problem in the above areas cause a HP loss, & idle rpm would decrease, not increase.

Somebody said engine may have 273 heads. Didn't early heads have a different intake bolt angle? Bolt diameter? Could this be a problem?