My car has a 440 out of a 67 GTX , heads are out of a early 70's police car . It is 30 over, small cam, small intake , carb is a 780 . After checking the timing it was 7 or 8 BTDC . My chilton shows 3 440 timings 2 of them were 2.5 BTDC and 1 was 5 BTDC . Car also has Mopar electronic ignition . I put it in and set the timing years ago . Did I set it at 7.5 because the electronic ignit or should it be 5 or 2.5 . Anyone have any input on this . Car is now set at 2.5 , starts right and sounds more responsive .Thanks for reading this and any help .