68 C10 Wheel Backspace - Need Help

[wpotter]

I have a 68 C10 with ECE 4/6 drop. I also have a 72 rearend and front disk brakes. I just ordered a set of billet wheels and wanted to double check the backspace they recommend. The truck is apart so I can not measure like you are supposed to. Rear are 20x10 they say 5" backspace. Front are 20X8.5 they say 4.5" backspace. In trying to read other threads it looks like maybe 5.5" in the rear and 5" in the front would work better. Any help will be appreciated. Pictures would be good to. Thanks everyone.

[michael bustamante]

i would think a 5' backspace in the front would require you to trim down the lower control arm. even the 15" rallyes 15x8 are close to the lca`s and i think theyre a 4.5" backspace

[Mike C]

I would think that was a non-issue with the 20's since the rim is so much further away from that stuff, but not positive.

I have 17x8 with 4.5" backspace on the front of my '69 and I have 17x9 with 5" backspace in the rear. Front tires are 235 55 17 and rears are 275 55 17 and I have no clearance issues. My truck is a stepside and has been converted to 5 lug using a '71 rear axle.

2" springs, 2 1/2" disc spindles in the front with a DJM flip in the rear (leaf spring truck) that netted 7" drop.