Demon 340 vs Camaro 396 (400)
As I recall my friends Rod Greene 4 speed Demon ran low 13s a few weeks old.
With Headers/ Gears/Blueprinted stock lift cam/ small slicks it set the J/SA NHRA National Record at Fremont Cal track = 11.88 @ 113.32 way back then.
As i recall it was 1972 with lower compression and smaller valves than 70/71 340s
I think he is on here sometimes.
I agree that 13.39 is not special - especially for a car not torn done and NHRA certified legal = Just stock appearing.