I have a 1985 , 3.0 with a 400 stringer drive trying to chase down why i do not have more than 23 mph at 3800 rpm. This is what i found my dis. Cap is very worn and it need plugs. First question is what is the plug gap i know the pints are 18.000. Also i do not think the shift interupter s set rigth. It shifts fine but if i ease into it the interrupter misses untill i can play with it untill i reach a higher rm past the interupter. Any help would be great. I should also tell you the prop is a 13 1/4 x 17