4500 ????? I ran 1 of those buggers in a dirt modified for years, tall deck, stock crank,Eagle rods. square port closed chamber heads,14.5-1 pistons on methanol, turned it 7200 on a regular basis for at least 6 seasons with nuthin more than rings & bearings once a season, still got it over in the corner just waitin for a 55 chevy some day...