Trailing arm perch spacing.....measurement.

[spudder]

I've searched but haven't found the center line dimension between the trailing arm perches. Planning on swapping a mid '80s rear end into a '64.
I want to go ahead and get the rear end modified for the swap by adding a panhard bar bracket and the trailing arm perches.
The truck is going to be at stock height so pinion angle won't change.
Can anyone provide these measurements:
1) trailing arm perch side to side center line distance
2) original pinion angle

I don't have an original rear end here to measure. That's why I'm requesting help from the forum.
Thanks