Thanks. Ive been there with the ignition system too. Replaced everything. Wiring harness, coil, all new distributor, cap, rotor, wires, plugs, everything....same problem. Also replaced all the sensors. Its still bogging and backfiring at the carb under light acceleration, and blows soot out the exhaust until it warm up. I just swapped the power valve and jets with the OEM carb I still have. Same problem. I also had an adjustable cam timing gear which was on the advanced 1.5 deg, so I put it back at 0. Car started easier but still boggs, etc. I may try a 6.5 power valve just for fun...I also checked compression. All cylinders same and good. Sux!!!! Ill try the perth recommended mechanic. Thanks for the help.