Still confused
 

Im installing a Moser rearend behind a 406 SBC with Turbo 350 with a GV overdrive unit and a shortened drive shaft and have 3.5 down measuring from the starter on the engine which I read is an acceptable place to measure from for trans and the rear is -2 measuring using the vertical pinion yoke. This is on a lowered 67 Camaro. Reading this thread I need to shim rearend 5.5 degrees up to be correct. Is this correct and do I need to be concerned re working angles? Thanks for any assistance

Yes, but I would take advantage of all the tunnel clearance you have. If you can achieve 2-3 degrees of drivetrain angle you are better off as long as you working angles are ok.

Thanks, do u think the measurement from the bottom of the starter is ok for transmission angle or would it be better or possibly different from the tailshaft housing of the GV?

You're better off using the harmonic balancer, oil pan rail, or better yet ujoint at the transmission yoke. You just need to make sure its at 90 degrees to the floor. Then you can use a socket that fits and is flush on the ujoint cap.