Sounds like you need to do some checking.
Get the engine to TDC on the #1 cylinder and check that the timing marks line up at 0 degrees. That'll tell if the balancer is slipped. If so, time for new balancer.
If thats OK, then remove dist and check for proper movement of vacuum advance, mech advance, etc. Repair and reinstall dist.
Fire engine and set timing to proper marks. 10 degrees BTDC is a good starting point. If engine runs funny, look at fuel delivery and valve systems. Do a compression test.
OH, and 6 volts at coil is correct with most petronix conversions.
goodluck
chip
