[redhawk44]

Originally Posted by dataway

I think if I had the same problem (the noise), and couldn't identify it by listening I would.

1. Turn it over with no plugs and listen ... still makes the noise ... then
2. Turn it over with no plugs and the distributor and oil pump drive removed ... noise disappears, you have a solution, noise doesn't disappear you know there is probably a part clearance issue somewhere deeper inside.
3. Only makes the noise with plugs and running ... figure probably combustion related, then....
4. Check yet again for exhaust manifold leak, crack, exhaust port leak/ crack. No luck .... now you are beyond my knowledge to diagnose.

I'd do it all with no belts installed, and AFTER any tuning issues are taken care of.

This is not a comment about this particular situation at all, just wondering if that would be the proper assumptions to make in a similar situation.

This approach makes sense.