Not knowing much about EMPs, would that affect a carb system or just sequential fires with chip a lots under the passenger seat
Carburetors are non-electric (except for the choke, in some cases), so that's always a better bet than an EFI-equipped car. Carbs were still in use up until the mid-1980s, but by then all the cars had electronic ignition (not computerized, but the circuitry is probably vulnerable). Any carbureted vehicle can probably be fitted with an older distributor (breaker points and condensor).
Downside... the kid at Pep Boys looks at you funny when you ask for "points" or "condensor". You get the "thousand-yard stare", every time.