340 compression variance

I tested the engine warm and put about 3000 miles on the engine since I bought it so it is what it is. Are the variances considered bad? My initial thoughts are break it down, inspect it, have the heads inspected, then go from there.

Meh, I think they would be normal considering that it had a long dormant period. That doesn't do valve springs any good, either. Some open. For 16 years? Even with hydraulic lifters that bleed down, some will still be open and that will weaken them. You might try dumping a can of Sea Foam in the crankcase and in the gas tank too. Run it for an entire oil change in the crankcase. Couldn't hurt.