Vacuum Leaks - Possible Fixes ?

[ARCHINSTL]

OK - some umbday questions about vacuum leaks, but I just gotta ask before I go bonkers.

1. After installing a new manifold gasket (and using a straight edge on the manifolds), I still have a very small leak at the front intake port. I have retorqued/checked the torque on all nuts/bolts 4 times now (18ft.lbs cold). This leak is present when starting the engine, and not just at normal operating temperature. I checked it by using the brake cleaner spray method. Is a "little" leakage normal on the 3AC? I would not think it would be so, but ? ? ?
And - wild question - is there a product that be applied around the joint to eliminate the leak? Possibly a product like muffler seal or "plastic steel"? I feel embarrassed asking this q., and no, I don't buy the devices which put ions in the gas line to improve power and mileage...

2. Re the phenolic plate/warmer directly under the carb: The electrical attachment is not an extremely tight fit in its slot, so I used some extra sealer there. I don't know if it is sealing enough, though. Has anyone used two of the thin gaskets between the plate and the heat shield? Again, I don't know if this is a valid fix for a possible leak, but had to ask.

3. A while back I thought I had eliminated the "surging" or "loping" the engine developed at 2000 +/- rpm by replacing the brake booster hoses, and did make a post to that effect. Well, the problem has arisen again. When revved to 2200rpm, it will immediately drop to 1800 and then just as immediately go back to 2200 and then continue to repeat this cycle unless taken above/below the 2200 point. This phenomenon occurs only at the 2200 rpm point and nowhere else in the range. Has anyone else experienced this? It certainly makes smooth driving awkward.

Thanks to all.
Tom M.