most usually can get away with is 5" BS if axle is centered , no two cars are ever the same so you might have more on one side than the other so that would be even less BS
and thats not rim BS but total BS with tire mounted measured at the bulge of the tire , youll need to pick a tire with little bulge or a section width less than 11 , and i beleive run atleast 1/2 -3/4 spacer (going to need long studs)
youll have to look at tire specs and see what the section width is on the rim they measured with and do some simple math
an 11" section width tire on a 9.5 (10.5 out side measure) there will be 1/2 bulge with your 5.5 BS thats 6 total BS , youll need almost 1" spacer
ive got 295/50 15s on back my 87 right now but im on an 8" rim and have rolled lips , ive seen the MT 295 16s ET street drag radials fit with 10" rims but again rolled lips and near perfect on the back space i think rim was 4.5"BS (it was the 16x10 GTA g body parts sells)
what type of tire did you want to run ( performance street ,drag radial or full slick .. and what height ?
, very little choice in mickey thompson tires for 16" rim
4.5 BS would have been a better choice
or do a frame notch then youll have lots o room