narrower rear, stepside bed, wheel spacing - The 1947 - Present Chevrolet & GMC Truck Message Board Network

whatnow123 · 05-23-2007, 01:41 PM

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!

stllookn · 05-23-2007, 02:23 PM

How low are you going to go with the suspension? I have an 11.125 in. (283) on a wheel that has 3.0 in. backspacing. My tires hit the outside of the wheel wells when I drop the bags onto the frame with no "c" notch. The tires tuck about 1-2 inches into the fender. If I were to drop it as much as I would like they rub really hard since the fenders slope into the body. I have about a 1.25 in. on the inside remaining before I hit the inside of the wheel well. So 4.0 in. seems to be about the maximum back spacing you could do without hitting the inside of the box.

My '67 stepside has the stock rearend. I would verify these measurements with another board member before you order your wheels however.

whatnow123 · 05-23-2007, 05:14 PM

What I'm looking for is the rear tire to line up with the outside of the fender like Shock Me's truck that I have a photo of. He is running a 71-72 rear axle with 5in of back spacing on his wheels. His rims are also 9.5's and we have the same drop. Since I have the narrower axle, I was thinking 4" back spacing and 10 wide rims is going to get me really close to this.

I believe that the axle differences between the later and earlier axles are 1.6 inches per side narrower.

**Shock_Me** · 05-23-2007, 08:29 PM

Whatnow,
It doesn't really look like it in this picture of my brother's stepside, but if he hit the right bump, these tires might rub. We're thinking that 5.5" of backspace would have been better. It would be real close to the inside, but the outside should clear the tire.
Luckily he has a buyer for these rims, so we'll probably try the new theory. I'll take better measurements this time to be sure though.

Pete

05-23-2007, 01:41 PM	#1
whatnow123 Registered User Join Date: Oct 2006 Location: Arizona Posts: 835	narrower rear, stepside bed, wheel spacing 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! __________________ 67 Short Step, 355, 700R 4.11 posi rear, 4/6 drop Discs on all 4 corners. Build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=219094

05-23-2007, 02:23 PM	#2
stllookn Saving 1 truck at a time! Join Date: Aug 2001 Location: Kent, WA Posts: 6,465	Re: narrower rear, stepside bed, wheel spacing How low are you going to go with the suspension? I have an 11.125 in. (283) on a wheel that has 3.0 in. backspacing. My tires hit the outside of the wheel wells when I drop the bags onto the frame with no "c" notch. The tires tuck about 1-2 inches into the fender. If I were to drop it as much as I would like they rub really hard since the fenders slope into the body. I have about a 1.25 in. on the inside remaining before I hit the inside of the wheel well. So 4.0 in. seems to be about the maximum back spacing you could do without hitting the inside of the box. My '67 stepside has the stock rearend. I would verify these measurements with another board member before you order your wheels however. __________________ '68 C20 Longhorn 50th Anniversary 400/TH400 '68 C20 Longhorn 50th Anniversary 468/TH400w/buckets '72 C20 Halfhorn (Longhorn w/o cab and front clip) '69 Flxible Cruiser (look up ugly in the dictionary)

05-23-2007, 05:14 PM	#3
whatnow123 Registered User Join Date: Oct 2006 Location: Arizona Posts: 835	Re: narrower rear, stepside bed, wheel spacing What I'm looking for is the rear tire to line up with the outside of the fender like Shock Me's truck that I have a photo of. He is running a 71-72 rear axle with 5in of back spacing on his wheels. His rims are also 9.5's and we have the same drop. Since I have the narrower axle, I was thinking 4" back spacing and 10 wide rims is going to get me really close to this. I believe that the axle differences between the later and earlier axles are 1.6 inches per side narrower. Attached Images __________________ 67 Short Step, 355, 700R 4.11 posi rear, 4/6 drop Discs on all 4 corners. Build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=219094

05-23-2007, 08:29 PM	#4
Shock_Me Senior Member Join Date: May 2005 Location: New Brunswick, Canada Posts: 591	Re: narrower rear, stepside bed, wheel spacing Whatnow, It doesn't really look like it in this picture of my brother's stepside, but if he hit the right bump, these tires might rub. We're thinking that 5.5" of backspace would have been better. It would be real close to the inside, but the outside should clear the tire. Luckily he has a buyer for these rims, so we'll probably try the new theory. I'll take better measurements this time to be sure though. Pete Last edited by Shock_Me; 05-23-2007 at 08:31 PM.



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