narrower rear, stepside bed, wheel spacing

[whatnow123]

Hi Everyone,

Can someone tell me if 4 inches of backspacing is enough for rear wheels? I want to order my rims since they are going to take 8 weeks to be built, but I don't have a reference point at the moment as I don't have the bed on it and can't put it on at the moment.

The truck is a 67, so it has the narrower 6 lug axle and a stepside bed. I want to run 17 x 10 rear rims with a 285 tire. I have 15 x 8 rims now with 4 inches of backspacing with 60 275 tires on the front and rear. The inside measurement on the rear tire bulge is about 2 inches wider than the inside measurement of a stepside bed so I think I'm safe.

I want to get 17 x 10 with 4in of backspacing on the rear, 17 x 8 fronts with 4in backspacing on the front. I have early classics drop spindles on the front which I'm told widens the front track width (outside to outside) about 1.5in. I like how the front wheel are on the truck, but I want the rear to have the same outside track width but I'm not sure if the I'll have rubbing issues with 4 inches of backspacing.

Any advise at all would be appreciated!