Stock is 140 but I several on the forum have said that they got a 150 on theirs with no rubbing. I don't know if I would bother with a 10mm difference, but then at $3500 for the FBI kit, I think that's a mod that's out of my price range.
swapped out to a stock 140 Dunlop Elite 3.... same width as stock, but LOOKS wider...
word of caution when going to a wider tire... check the load rating first.... road glides are heavy, add a rider, gear, etc... they can over whelm a tire that isn't up to the load
Keep in mind its a softer compound tire than the Dunlop. I dont get nearly as many miles out of it. Got 5000 out of my last tire, Im on throtle pretty heavy though.
I run a Metzler 160 had to trim a little off the plastic belt guard. Had a Avon 150 before had same experiance as pittz5 about 7,000 miles on it. Metzler has a little over 10,000 and need a new one. Also very heavy on the throttle.
I run the 160 metz on an 18X4.25 wheel on my '06 roadglide. NO problems! The 160 is a softer compound than the 140metz as others have said, and I wear them out in 6K. They are sticky though! LOL!
Jason