Msd Cap adapt question

[Duane]

does anyone know if this larger diameter will clear the firewall of my 1968 dart with a small block in the stock location. I have no motor in the car and am contemplating this cap system, but I know the clearance is already close on A body's with small block engines.

 

[Duane]

Ok could someone take a measurement for me. Just a tape measure of how much distance between your stock distributor and the firewall would help.
Thanks