Sounds ignition related to me. Fuel issues tend to be intermittent, causing it to cut in and out, not shutting the car off as you're describing.
Rule #1 for me is to check the last thing I did to the car after a new problem arises. Typically, it's something related to what I just "fixed." You mentioned recently changing to a Pertronix setup. What were you running before, and did the problem happen with that old set up? If it was fine then, I'd swap the old set up back in and start driving the heck out of it again. If the problem disappears, you've found your culprit.
Hope that helps. It's where I would start.
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Eric "Todd" Mitten
'74 Bonneville 4dr Sedan (455/TH400/2.93 open)
'72 LeMans GT (455/M-13/3.23 [8.5"] posi)
'71 GTO Hardtop (400/TH400/3.07 12 bolt posi)
‘71 GTO Convertible (455HO/TH400/3.23 posi)
'67 GTO Coupe (455/ST-10/2.93 posi)
'67 Tempest Wagon (428/TH400/2.56 posi)
Deuteronomy 8:3
