I have been running mine at 3550-3600 RPM for over 350 hours now with a turbo and no problems whatsoever. For a tachometer I used one of the Glowshift Diesel Tachs that go off the alternator. Just remove the alternator, take the cover off, and put a wire tap off 1 of the 3 phases of the rectifier. Then use a photo tachometer to calibrate the guage. Mine is +/- 10 RPM from the phototach reading.