If you are building a trailer you may want to consider that you may later choose to upgrade to a C-series offset wheel for more stability, wheel spacers or even a long travel kit. You don't want to limit yourself for possible future modifications.
To your question, I cannot give you an accurate measurement per your specifications as I have c-series wheels and 1-1/2 wheel spacers.
Good luck, Matt
05 Rhino -Beadlocks,26" Bighorns, wheel spacers, Custom 2" lift, Dynatek CDI, Aftermarket Sheave, 4 PIAA Halogens (Sold)
02 Yamaha 660 Grizzly
-6" Gorilla lift, snorkeled and Outlawed Pics: ( FOR SALE )