Hey Darren, here is a copy of an E-mail I sent to Gene with my measurements.
How does it compare to what you have?

"Hello Gene, Jackson here from Moparts.
I have some measurements here for you.
With the pedal up to the rubber stop I have 4.25" from the end of the threads on the heim joint and to the end of the threads on the hydraulic masters threads.
The adjustment rod that you have supplied is 4.25", so I think that a threaded push rod of 5.5 would do the trick.
That will give me a travel of 1.25" of the push rod, from the stop to the pedal on the floor.
How does this sound to you?
I will post this as a reply on the Moparts thread 1971 Challenger Conversion from Auto to Manual. Just in case Ludington1 needs to see it to help him."

I see what you are saying about the brake light switch hitting the heim joint, but I would like to keep my push rod as straight as possible.
So I think I will have to figure something out with my brake light switch.
Hey Dayclona! Any ideas? Since you are such a pro at this install.
I would hate to spend time reinventing the wheel.