Will 15" x 10" wide rim with 4" backspace fit with stock rear?

[88Stanger]

Originally Posted by SCOTI

I switched to the narrowed rear housing specifically to allow using a 10" wide wheel w/4" BS & not have to cut up the inner bedside. The bed is also mini-tubbed to fit the rubber.

Please excuse my ignorance, but what is meant by narrow vs wide rearend?
PS thank you to all of you for these great responses.

[SCOTI]

Originally Posted by 88Stanger

Please excuse my ignorance, but what is meant by narrow vs wide rearend?
PS thank you to all of you for these great responses.

The 'early' truck 12bolts changed width as disc brakes came along. At some point in '70, the rear ends started being made 1.5" wider vs. pre-'70. So, 63-69 rear ends were the narrow 12bolt. In 1970, as production started building things for the new '71 models (that would now have standard disc brakes up front), the housings were wider width but w/6-lug axles. Starting in '71, the axles changed to 5-lug.

Since these trucks are so old & parts are easily swapped between the years, you have to pay attention to what you have & not assume just because it's 'X' year model, it will work. From what I learned:

63-64 'narrow' 12-bolt 17-spline axles
65-69 'narrow' 12-bolt 31-spline axles
70 could be either the narrow or wider by 1.5" 12-bolt 31-spline axles
71-80 'wider' 12 bolt 31-spline axles

Any of the above from 63-72 could be truck-arm or leaf housings. The additional width was outboard of the T/A or leaf mounting pads.

81-87/91 'wider' 10 or 12 bolt
In 88, the C/K GMT400 style rear housings/axles got an increase in width again by 1.5".

So, if you have a truck that has one of the possible '70 model wider housings swapped in prior to your ownership, things are different vs. something that came as factory. A buddy & I learned this the hard way (after he spent $$ on new wheels).

[joe dirt]

these are 10" wheels....unsure of backspacing tho

[SCOTI]

Originally Posted by joe dirt

these are 10" wheels....unsure of backspacing tho

Looking @ this pic, the rears don't seem 10" wide. Could just be an angle/view perspective thing. What size tires & how much/how was it dropped?
On mine, there's ~1/2" clearance out-board of the sidewall w/the stock bedside opening lip. Any mods to the one in your pic?

[joe dirt]

Originally Posted by SCOTI

Looking @ this pic, the rears don't seem 10" wide. Could just be an angle/view perspective thing. What size tires & how much/how was it dropped?
On mine, there's ~1/2" clearance out-board of the sidewall w/the stock bedside opening lip. Any mods to the one in your pic?

rear tires are 255/60/15

rear is dropped via removal of springs in the pack....( gmc truck ) unsure how much, I got it this way....


edit, I actually think these are 15x8 neg. offset now that I think about it

[SCOTI]

Originally Posted by joe dirt

rear tires are 255/60/15

rear is dropped via removal of springs in the pack....( gmc truck ) unsure how much, I got it this way....


edit, I actually think these are 15x8 neg. offset now that I think about it

It didn't seem like a 10" wide wheel. Photos on the screen are difficult to get the right view sometimes though. They looked like ~8" wheels w/about 3-3.5" BS to me. A 255 section width tire helps as that seems about right for an 8" wheel.

[LostMy65]

Originally Posted by SCOTI

It didn't seem like a 10" wide wheel. Photos on the screen are difficult to get the right view sometimes though. They looked like ~8" wheels w/about 3-3.5" BS to me. A 255 section width tire helps as that seems about right for an 8" wheel.

Here is a side by side.