But if you run same tire as on the 8" wheel you will have less sidewall bulge giving you more tire clearance off the spring. I'm running a 10" wheel on my Demon it has 5" back spacing but I also have the springs moved in 3/4" and disk brakes on the rear that puts the wheels out about another 1/4 to 3/8 more than stock I think 5.5" of BS would have been better in my application as I have almost 3/4' space to the springs and a little rubbing on the outer fenders on bumps.
I always like to mention that back spacing between manufactures is not always measured the same. Centerline on the drag wheels seems to measure from the far inside of wheel lip with a straight edge to the hub mounting surface to get back spacing. Other manufactures seem to measure from inside wheel seat lip to hub mounting. about a 1/2 difference between the two different methods. I'm assuming your probably going back to same wheel style so probably not an issue but worth noting anytime talking back spacing
