This is 1965 factory stock 273 Carter AFB, 273 factory intake, 273 factory exhaust manifolds on a stock rebuilt 318 short block with 2.5 inch TTI dual exhaust. Only about 2,000 street miles on re-build which, up until now, had a rock-solid smooth idle but now shaking noticeably at idle. Warm compression check shows six cylinders @ 160 PSI, one @ 150 PSI, and one @ 165 PSI. Wondering how plugs from cylinders 1, 2, 3, 4, could be so dry sooty black while the other cylinders (rear four) have normal whitish/tannish looking plugs? (choke is always tied open permanently by the way)
