371 build W/Big Mouth heads

yellow rose said

It's nitrided. That helps. Faster lobes need higher spring rates. They die just as quick from spring pressures too low. I've run 180 on the seat with a SFT. It lasted over 150 runs and that's a lot of spring pressure for SFT's

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Yeah I caught that after posting, and good idea on that ramp.180? What lift? thats stiff for street sft, but not for race. Most of the faster sft grinds I've used in motors over the years all set at 150-160 seat, highest being 170....but that didn't work out long....but not dabbling in nitrate or shubeck, composite etc...so for me "fast don't last" comes from a few or so trips for a regrind when a lobe or two starts showing through, usually much longer than 150 passes....so....just give it some time.