I would pull that engine down and check the ballance. In "the old days" they only ballanced to (1-4 grams) 'or so'. Today they get it 'on the money.'

There's a good reason why he said "shift at 5800" & that could be it. Check with "frenchtown" too.

It's a lot cheaper than another engine/starting over.

Good luck. \:\)

John M., I.I. #3370

"There are no shortcuts to any place worth going". -Anon