I've had my '71 Duster engine rebuilt, as well as the Holley 1 bbl. carburetor. The mechanic I use suggested that I use Pertronix Distributor, and go pointless. It seems ever since, my idle has been very rough. Idles too fast, and really rough. 1.) Electrically- - - completely new wiring harness throughout car, new alternator, spark plugs, coil, ignition wires. 2. With regards to fuel intake- - - Rebuilt 1 bbl Holley Carburetor, new vacuum lines, hooked up properly, new fuel pump, new fuel filter, new gas tank ( total parts). 3.) With regards to exhaust-- - new exhaust manifold, new single tailpipe, new muffler, and continued new tailpipe to rear bumper. I don't know what is going wrong. Any suggestions /advise would be welcome.