I think you owe it to yourself (and your bolt) to adjust the valves, Tom. For me, I've had to adjust the valves about every 12 - 18 months, waaaayyyy less than 5000 miles. I do it when the clacking gets noticeable, and after doing the adjustment, notice immediate power improvement. Before doing the adjustment, my power loss is so gradual that I don't really notice it until I've done the adjustment.
It's free to do- if nothing else, you can "check the box" that valve adjustment is NOT part of the problem.
You also should confirm your timing is set right. If you don't have a timing light, usually you can borrow one at a local auto parts store.
Double-check your vacuum hose connections to make sure you don't have a hose that wiggled loose. I'd check at the fuel pump, the carb base, and the vacuum wiper motor.
Bill
