Ok here is a bunch of pictures. Some are not the greatest and sorry about the dust.
As you can see the center of the tail shaft was darn near level with the inner two bolts that hold the crossmember on, it was just 1/8" above them, after the mod I am 1-5/8" above them (have so double check that as that is what I had doing a mock up before actually cutting the crossmember)
I got this info from a member at Moparts, but they don't seem to add up, would be nice if someone here could measure a stock car
I measured my 71 Challenger, factory 4spd set up, all factory parts,...measuring from the output shaft centerline at the tailshaft to the top of the tranny sheetmetal hump (the hump center in the car is the same, 4spd or auto, as this is part of the original floor that is not cut for a 4 spd hump, factory or not) is approx 3 1/2"...now sheetmetal can vary between vehicles, so I also measured from the inboard transmission crossmember bolt, up to the tailshaft/output centerline, this is approx 3"
You can also see that I had to replace of the bolts that hold the shifter bracket on with a flat head reccessed one. You can see where the normal bolt was scraping the paint off the frame.
It is hard to take a picture of the difference in the bubble, but it did help ALOT, I still need to gain about 1/4" in the back. Also before the mod the fan was very close to hitting the top of the readiator shroud, now I have some cleanace.
The tunnel is a little rough looking I know, not what I wanted but I wanted to do as little as possible to disturbing the pain job. Also I am pretty shure I am going to have to mod the console because it is going to be hitting the tunnel on the drives side holding it up. So I am going to have to trim some off the bottom of the plastic.