Adjusting brake p-rod

Somewhere in the process of a complete rebuild of my old car I swapped Master cyls, put an offset adapter/spacer on it etc...along with a retainer/catch, the pushrod will likely need lengthening. On the bench mock-up, I've added a short length of tube to the rod's end to 'compensate' for the added stack-up. While it seems to hit a point of resistance, there still is mechanical travel left in the master. HOW DO I SET THE PUSHROD LENGTH FOR PROPER TRAVEL? Thanks in advance!

Sean.. with it in the car does the master
have just a short bit of travel before your
pedal bottoms out (no fluid in it).. what do
you think you have for free travel before you
get any resistance (free play)

I never had fluid in it...I only ran the lines and was going to put a retainer on it and noticed the travel issue. It is now 'assembled' (pedal bracket and all) in my vise on the bench.

So you have the whole assembly ready to go
on the bench.. how much free play till you
get that small resistance.. also see if you
can get full piston travel using the pedal..
should be close to bottoming
EDIT
I set them so you have almost zero free play..
its like .020 play.. just so it doesnt push
on the piston

Dr Diff sells an adjustable rod.

Thank you all...I called Strange and what I have been unable to express here was...WHAT IS THE TYPICAL PISTON TRAVEL distance of a/this master cylinder. There answer was approx. one inch. I had NO BACKSTOP to set 'lash' in my 'previously modified' brake system by...? Now it all makes sense to me. Thanks again for your input!