Need a few dimensions off of a leaf spring car

[MAStuart]

HI! I have been scratch building a leaf spring car (Daytona Coupe). I finally acquired the differential mounts. I tried mounting the differential. For the side mounts, the bolt slid in perfectly. I am having problems with the front mount. The front mount is interferring with the cross tube that is supposed to have the tabs for the front mount to mount to. I can't even bolt the front mount to the differential. There is not enough room. I have a problem, either the cross tube is in the wrong position or possibly the pinion angle is wrong. My question is to anyone who would know or has access to an original small block car, what would the measurement be between the front of the rear spring tower and the cross tube that the front differential mount tabs weld to? Another question, what diameter is the tube of the front differential mount? Does anyone know what the pinion angle would be on a leaf spring car? What I have built so far is exactly to the prints I have. I know this should have been checked before everything was welded together, but I did not have a differential or mounting brackets at the time. Now I am loosing sleep on where I went wrong. I will try to post a couple of pictures of the measurement I need. Thanks Mark