Thanks Mike! I totally agree with you, a mock up is best. The engine is currently out of the car, but the winter is long, and I have time to swing the engine in,along with the bellhousing, transmission,and rear crossmember,and be sure. I'm afraid of an unwanted "surprise". A trial fit is best.
Also, I had the opportunity to look at a friend's 70 Roadrunner, a factory 4 speed car.This car was pristinely painted, awaiting assembly,I could only look in the window,but he carefully crawled inside, and gave me some measurements, I couldn't see underneath, but I did notice, that the hump was welded, with 1 1/4" to 1 1/2" long beads. and a similar gap between the beads. The welds were along the hump's edge to floor. Nice n strong.
Thanks!
Paul