The tire has been removed from the old wheel so it made it easier. I put the front of the wheel on the garage floor and layed a straight 2 by 4 on the back side of the wheel and measured from where the wheel hits the brake drum to the bottom side of the 2 by 4 and came up with 5 inches. I think I did everything right. Does anyone else have any other ideas? The new rim is currently mounted on the front and it doesn't seem to hit anything and especially the tie rod end. I turned the steering wheel all the way to the left and right and it seemed fine. I didn't measure the backspace of the new wheel because it is a little harder with the tire on (I didn't have the right size scrap piece of wood to just lay on the back side of the rim without hitting the tire). Did I measure right or do I have a unique wheel. Everything appears stock. I have the original GMC hub caps for it to. I also have an old rusty 66 GMC and everything looks identical between the two. The reason I am asking is because if someone already is using newer 2000 era wheels on their 3/4 ton I would like to buy some used steel wheels for mine. I would like to know if they truly do work or not. Please tell me.