wheel back spacing info

[stroker52]

now that im changing over the the 5on4 3/4 bolt pattern do to the wheels im getting from weld racing i need some help with back spacing. the truck is doing to be dropped 4/6 big sway bars front and rear with QA1 shocks on all for corners. but im un sure on the back spacing ive done some searching and see most are using 5.5 in the rear and around the same on the front. i have the lip trimmed off the front fenders and welded back up.

i will be running 18's on all 4 corners 8.5 in front and 10's out back..