I really like this list server. You can through out a topic and sit back and get all kinds of opinions.When I started building engines wide open throttle Was 3000 rpm.We were working with small bore long stroke engines (under square) and we built them tight.Babbit coated bronze bearings and high ring pressures had to be set up tight and run in.When you bought a car back then it came with run-in instructions.I personally would not let S.T.P.come anywhere close to a fresh engine even today with modern engines, as I feel it would hamper break in of the bearings and rings.It would be fine with a cam change on a engine that was already broken in.Roger does the high pressure cam lube claim not to interfere with break in? There used to be a parts store in the city that had a machine shop in the back. They would build up the block-crank-rods-pistons-and-cam.No heads or pan put on a stand in a Plexiglass container ,Flow oil from a separate pump into the cylinders top and bottom with the stock pump supplying oil to the bearings turn the engine about 2 or 300 RPM with a electric motor and run it for 72 hours.This was done in front of the parts counter .I don't know if it really worked I did not think the oil was hot enough but it sure was fun to watch. Jim McMullan. --- --- EarthLink: It's your Internet. [Non-text portions of this message have been removed]