67 Dart Build Triangulated 4 link & Mini Tub

Not sure I get what the issue is then.

I'm thinking this is like a Dana 60 deal where the drivers tube is 1 3/8 longer than pass side to get the pinion located properly. If you have the pinion in the correct location, the tubes may very well be different lengths.

Huge tolerances in these cars too. Not surprised by the measurements.