I finally have my new floor pan patches welded in place and am ready to add the new seat risers. With the time gap from cutting out the old rusty crap to now my markings have been erased more or less. I have a good idea but would like to know if there is a precise measurement available?
Either reference on the side or from front. I am sure I am not the only one who has been here 
I am using the ones from WCCC and have a 68 XR7.
I know this is not a “sexy” topic but sure could use a few pointers before I start welding th I weekend.
I don’t have precise numbers, when I did my passenger one, we used the driver as an example. Looking at the floor there isn’t a great reference point and I have two layers of insulation in place so my measurements would be off.
Did you buy repro or used? Keep in mind the repro is actually Mustang and one inch taller. Great for some but miserable if you are 6’4" like me. Just line the 4 seat track holes up with the four holes in the pan. The factory rarely got it perfect so don’t over think it.
Don, thanks for your reply. I bought them from you, WCCC. I am actually happy they are taller as I am not nearly as tall as you!
I figured that I might be trying to over think this a little too much. Also, thanks for the nice black WCCC Beanie cap I received with my last order!