I've been toubleshooting this shakey engine for 2 weeks now and cant seem to make any progress. I have noticed some black residue on the inside of distr. cap right in the center. Brand new acell dizzy. Ive installed new edle carb and intake, new wires and plugs. Check for vac leaks, none found. I have no smog stuff or ecm on the car. Adjusted valve lash. Timing at 12btdc 34 deg at 2500rpm . Engine has great power at WOT.Anyone got an idea?