Yeah I agree totally, get a compression and leakdown test done. Even just a compression test (simple, just a gauge needed) will give you a pretty good idea of the internal condition of you engine. Too bad you live in Colorado. If you lived out here by me (variously NY and DE) I'd say bring it over my house and I'll check it out for you.

When you get the test done ask them for what the numbers were for each cylinder and post them here. Also good to know would be if the readings increased when oil was sprayed into the cylinder. (this is called a wet compression test). If the wet compression numbers are significantly better than the dry numbers it indicates worn piston rings. The oil will temporarily improve the ring seal, giving you higher numbers. If wet and dry are about the same and are low, the valves are teh culprit.