[66benchcoupe]

I forget. Since I'm running all mechanical advance I don't use the vaccum ports.

My motor.
Black primer 66 coupe, bench seat
Balanced&Blueprinted 5.0, F303 roller, Trick Flow heads, Demon 650, MSD
C-4, 3.55 TSD. 2.5" pipes, Dynomax Super Turbos

 

[66benchcoupe]

Get a reprint of a 1967 FORD shop manual. Plug should be gapped at 0.032-0.036". Timing should be 12 degrees for a 390 GT, 10 for a non-GT, without emission controls. If you're running a Pertronix the you can go to 0.045", maybe more. I'm running 0.55" with my MSD. If you're not running a Pertronix then you need a dwell meter to accurately check the dwell. Don't rely on gapping the points. Remember dwell effects timing and vice versa. You should be able to pick up a Sunpro timing light and dwell meter set for $40 or so.

My motor.
Black primer 66 coupe, bench seat
Balanced&Blueprinted 5.0, F303 roller, Trick Flow heads, Demon 650, MSD
C-4, 3.55 TSD. 2.5" pipes, Dynomax Super Turbos