6 lug disc conversion, wheel backspacing

[chev-obsession]

I've converted my 65 1/2 ton using baer brakes kit, lowered 2.5" in the front using mcgaughy's drop spindle and 5'' (I think) in the rear with a spring. I threw a set of wheels off of a newer chevy avalanche and it looks like the wheels in the front stick out about 2'' past the back wheels. I've searched and found some rotors that offered different spacing, but that's not an option for me.

Is this is a common issue when lowering these trucks or is it the wheels? as far I know the wheels on the truck are the same back spacing now.