FYI, accelerating at 75-80% load, as reported by the
scangauge, corresponds to about 12 psi MAP. At 1500-2000 rpm, that's the optimum BSFC point for most engines. Useful for P&G. A simple vacuum gauge won't tell you about P&G, it'll tell you to use super-light throttle all the time. That's good, but not always the best. Do some reading about P&G and about BSFC.