Thanks Robert for the reply. I probably gave the wrong impression that the rpm suddently went up between 65 adn 70 mph. Actually what I mean was at 65 mph, rpm was 3,900, at 70 mph it went up to about 4,100 rpm. It was 3,800 and 4,000 before head replacement. No sudden movement of the rpm.

Leo

Robert Cardo <rrecardo@WEBTV.NET> wrote:
If the RPM has picked up at any given speed, it sure sounds like a
slipping clutch to me.
Not unless you installed smaller tires in the rear.