Wheel backspacing question

[mark289]

I have a 65 C-10 longbox step side. My wheels are currently 15 X 5.5 with a back space of 3.75, I want to put new rims on it. I see a lot of aftermarket rims with 4 - 4.5 backspace. will this work or will they rub on the backside? I was thinking about 17 X 8 rims and 265 55 17 rubber, will this fit back and front, and if I put disk brakes up front will this change anything?

[502tripower]

Originally Posted by mark289

I have a 65 C-10 longbox step side. My wheels are currently 15 X 5.5 with a back space of 3.75, I want to put new rims on it. I see a lot of aftermarket rims with 4 - 4.5 backspace. will this work or will they rub on the backside? I was thinking about 17 X 8 rims and 265 55 17 rubber, will this fit back and front, and if I put disk brakes up front will this change anything?

Your best bet is to measure the backsets yourself. You can do this by placing a framing square on the face of the brake drum/rotor and then looking at the measurement on the top of the framing square were it meets the wheel well. Then take a measurement with a tape from the back of the framing square to the inner fender/frame or the nearest point of contact. This will give you the overall width of your space. Then you need to find the cross section & height or diameter dimension of the tire you wish to use. The tire vendor can provide that information. Once you have all of those measurements you can determine your backspace. I am not sure if the disc brakes move the wheels out on the trucks. I know on the early GM cars they do. I am sure someone here will be able to answer that question. I think with a 8X17 with 4"-4.5" backset would probably work but I would most defiantly check before you go and order your wheels. It can be an expensive mistake.

[mark289]

thanks for the reply and the info, does anyone know if the disk brake kit will change the front end backspacing?

[SCOTI]

Originally Posted by mark289

thanks for the reply and the info, does anyone know if the disk brake kit will change the front end backspacing?

Yes, depending on the kit, back spacing will change. Typically, stock GM disc brake set-ups add 3/8" per side to the track width vs. drums. Aftermarket kits may or may not increase the track width depending on how custom the kit is.

[protrash64]

You can run very deep backspace on these trucks before having an issue. It will hit the bed before having problems in the front. I have 5.25" and 5.5" backspacing on my 2 trucks.

[mark289]

thanks for the help, it can be difficult to find info without this message board.