with BobR and others, your timing is way advanced. You want, on a bigblock, 38 degrees of mechanical timing in by 3000 rpm.

To those of you who persist in thinking every engine is different, you're wrong. I would have said the same thing about 10 years ago, but after studying countless engine buildups I have come to the firm belief that every combustion chamber has its own ignition timing characteristics. The mostly quiescent open chamber bigblock Mopar heads nearly always make max power with 38 degrees mechanical timing, add vacuum to get mileage at part throttle. Smallblock Mopar open chambers like 35-36 degrees, get some squish going and you can go down nearer to 30 degrees. Chevy Vortec heads, their 062 or 906 heads, make best power at 32 degrees.

If you twisted the timing for maximum engine speed you probably set the timing where it would be with mechanical and vacuum advance and it would be around 55 degrees. That's WAY too much ignition lead.

So, first get a decent timing light. A good inductive light is about $30. Then get the MP timing tape, costs like $6. Set mechanical timing at engine speed of 3000 rpm to 38 degrees BTDC with the vacuum advance disconnected and plugged. Then reconnect the vacuum advance and drive the car. It will run as it is supposed to.

R.