GL1100 carb rack measurements?

I'm still playing around with trying build a single carb manifold, and am looking for measurements from a factory rack. I would prefer not to take my carbs off to measure, since my wing is currently my only mode of transportation. The main measurement I need is the offset between the #4 intake port and the #3 port. Just looking at it, it appears to be around 1-3/4" farther forward on the #3, but I don't want to risk using the LAR (looks about right) method and wasting all of my aluminum tubing.
Thanks in advance!
Darren