I ran 15psi on a M44 up to 173K with no issues. I traded that motor as a core for my stroker motor. Metric Mechanic accepted the core and said it looked great inside many miles left on it. Trust me I real hard on my motors. I don't lift to shift, I keep the gas WOT banging the limiter, shift and slide my foot off the side so the clutch dumps hard on every shift
