Ive been looking and cannot find a straight answer, for a 15x8" prostar what backspace tucks and fits well? also with a 15x10 prostar will a 6" tuck and fit better than the 5.5" bs? thanks

 

15x8 will work with 4.5" of bs, front and rear. on the rear you can use a little more if you are using a fat tire.

the 10" wheel will fit pretty well with 6", but thats a hard size to find. 6.5 is more common, but you have to hammer/modify the inner fender well more or less depending on your tire size.

and this has been covered a million times...

 

i saw it both ways when i searched and didnt want to order the wrong ones