After running my 292 in stock form & tuning it as best I could for maybe 6 mo. & 6K mi., I changed the dist. vac. advance from ported to manifold vacuum. Had to set the dist. a bit back & experiment with it, but when done tuning, I have a lot more power right off idle on up thru the RPM range. Proof was that my MPG went up considerably. Also runs cooler in all driving conditions. This is in my 55 Bel Air, 3sp., & 3.08 gears. Doug