<VV> Tach out of whack and car runs like cr*p

[Padgett]

Measure the voltage on the red wire when revving. The Pertronix draws more 
power as the revs increase and may be dropping below minimum voltage at 
high revs. That would explain both the tach error and the cutout.

OTOH it is likely (have seen many) that the tach has a blown zener diode 
which will make it read non-linearly and differently with the P than points.

Padgett