Backspacing - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Hawker7 · 01-09-2009, 09:57 PM

Ok,I think I have decided to go with Torq Thrust II's with 275/60/15's all around on my 72 Long Bed. Anyone know what backspacing I should get? Some have said 3.75, while others have said 4.5. I called Summit Racing where I will be buying the wheels, and they said they have no idea. Anyone have any pictures of that setup on their truck?

**lolife99** · 01-09-2009, 10:55 PM

Hawker7,... What do you have planned for your truck?

Lowering it any? Do you have drop spindles? Stock height? 15x8(?) inch wheels?
A 275/60-15 is big on the front. Too big if it's lowered. All this stuff play into it.
Ever think about running a 15x7 up front and a 15x8 in the rear? Also if you have any pics of your truck,... that might help.

CG · 01-09-2009, 11:39 PM

Ive got the same issue going...check out this thread.

http://67-72chevytrucks.com/vboard/s...d.php?t=322718

**LEEVON** · 01-10-2009, 12:45 AM

Here's mine, 15x8 and the standard 4.5" backspacing. They don't stick out or anything, look great but I want something bigger. For sale (less tires) for $500 plus shipping.

**lolife99** · 01-10-2009, 01:05 AM

Man Leevon,... that thing is SWEET!

**LEEVON** · 01-10-2009, 01:08 AM

Thanks lolife, I didn't mean to jack the thread...his truck could look like mine with these very wheels on it though

my truck is actually a 10 footer, it's sporting 12 year old paint.

ps-I saw your new shorty, it's sweet. I'll have to stop by sometime when I'm up that way.

Hawker7 · 01-10-2009, 09:32 AM

Quote:

Originally Posted by lolife99

Hawker7,... What do you have planned for your truck?

Lowering it any? Do you have drop spindles? Stock height? 15x8(?) inch wheels?
A 275/60-15 is big on the front. Too big if it's lowered. All this stuff play into it.
Ever think about running a 15x7 up front and a 15x8 in the rear? Also if you have any pics of your truck,... that might help.

I plan on getting 15x8, and the truck is currently stock ride height. I do plan to lower it in the future maybe 2.5 up front, and 4 out back. From other posts I have read, people are running 275's up front with no issues.

Hawker7 · 01-10-2009, 10:26 AM

from reading some other posts it seems some people say 275's will rub up front, while others say they don't. Anyone running 275/60/15's on 15x8 with 4.5 backspacing all around???

**lolife99** · 01-10-2009, 01:02 PM

Quote:

Originally Posted by Hawker7

from reading some other posts it seems some people say 275's will rub up front, while others say they don't. Anyone running 275/60/15's on 15x8 with 4.5 backspacing all around???

Hawker7,... If you plan on running a 2.5" drop spindle,... a 4.5 backspace on a 15" rim will be a problem. (the inside edge of the wheel will contact the spindle in the lower ball joint area) People with 4" backspace even have this problem. On a bigger diameter rim it would be ok. (17" thru 20" wheels)
I just think a 275/60 will stick outside the fenders on a lowered truck, and cause rubbing issues. On a stock height truck they will be fine. Remember. The front "track width" on these trucks is wider than the rear track width.
My personal preference is a 7" or 8" wheel up front and a 9.5" or 10" wheel in the rear. It compensates for the different track width. (just my opinion)

Hawker7 · 01-10-2009, 01:27 PM

Quote:

Originally Posted by lolife99

Hawker7,... If you plan on running a 2.5" drop spindle,... a 4.5 backspace on a 15" rim will be a problem. (the inside edge of the wheel will contact the spindle in the lower ball joint area) People with 4" backsapce even have this proble. On a bigger diameter rim it would be ok. (17" thru 20" wheels)
I just think a 275/60 will stick outside the fenders on a lowered truck, and cause rubbing issues. On a stock height truck they will be fine. Remember. The front "track width" on these trucks is wider than the rear track width.
My personal preference is a 7" or 8" wheel up front and a 9.5" or 10" wheel in the rear. It compensates for the different track width. (just my opinion)

Have you run this setup and had issues? I'm just going by LEEVON who is running 275/60's on 15x8 with 4.5 backspacing and says he has no issues. I just don't want to buy any wheels and find out they don't fit, so that is why I'm looking for anyone who has run this setup.

**70cst** · 01-10-2009, 01:33 PM

I have a 2"/4" drop with spindles (disc. brakes) and I ran into rubbing issues on the front wheels with 8/15 GM Ralleys. I bought 8/16" TT II's with the back spacing and I forsee no issues. JFYI.

Hawker7 · 01-10-2009, 01:35 PM

Quote:

Originally Posted by 70cst

I have a 2"/4" drop with spindles (disc. brakes) and I ran into rubbing issues on the front wheels with 8/15 GM Ralleys. I bought 8/16" TT II's with the back spacing and I forsee no issues. JFYI.

what backspacing did you get?

CG · 01-10-2009, 01:37 PM

You might check out this other thread I had going also. Check out seetens truck

http://67-72chevytrucks.com/vboard/s...d.php?t=285491

**lolife99** · 01-10-2009, 01:39 PM

Yes,... I've had a 275/60 on a stock height truck. Lowered trucks will be different.
Search in the suspension section about wheels rubbing the lower control arms. It's been posted a bunch.
Most people buy their wheels and then lower the truck to find out they don't work.
If you're going to stay at stock height,... Leevon has the wheels for you!

Hawker7 · 01-10-2009, 01:39 PM

Quote:

Originally Posted by CG

You might check out this other thread I had going also. Check out seetens truck

http://67-72chevytrucks.com/vboard/s...d.php?t=285491

yep, he was one of the guys running that setup, so I'm confused as to why some people have issues, and some don't.

**70cst** · 01-10-2009, 01:50 PM

Quote:

Originally Posted by Hawker7

what backspacing did you get?

I think 4 1/2".

**LEEVON** · 01-10-2009, 06:44 PM

I'm running 3" DJM lower control arms, stock spindles which would explain why I don't have any issues. It's been so long since I lowered it and put those wheels on...clearance might have been the reason I went with the LCA's instead of spindles.

If I remember correctly, there is some light trimming to do on the drop spindles with 15x8 on 4.5" backspacing. I wouldn't want to start grinding on brand new spindles. But my setup works fine, Hawker I sent you a PM with the wheel pics.

CG · 01-10-2009, 07:52 PM

LEEVON those tires on your truck are 275 60 15's?

Hawker7 · 01-11-2009, 01:31 PM

what is the factory backspacing?

**LEEVON** · 01-11-2009, 03:24 PM

Quote:

Originally Posted by CG

LEEVON those tires on your truck are 275 60 15's?

You got me thinking...so I double checked the size. Hawker I have to apoligize, I've got 255/60/15 which would explain why I don't have any rubbing issues. My '87 has 275's at stock height.

Hawker7 · 01-11-2009, 03:35 PM

ok, so now will 255/60's work up front with the 4.5 backspacing and 275/60's out back? Is it the tire that rubs, or the wheel?

01-09-2009, 09:57 PM	#1
Hawker7 Registered User Join Date: Jan 2008 Location: Raleigh, NC Posts: 321	Backspacing Ok,I think I have decided to go with Torq Thrust II's with 275/60/15's all around on my 72 Long Bed. Anyone know what backspacing I should get? Some have said 3.75, while others have said 4.5. I called Summit Racing where I will be buying the wheels, and they said they have no idea. Anyone have any pictures of that setup on their truck?

01-09-2009, 10:55 PM	#2
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,717	Re: Backspacing Hawker7,... What do you have planned for your truck? Lowering it any? Do you have drop spindles? Stock height? 15x8(?) inch wheels? A 275/60-15 is big on the front. Too big if it's lowered. All this stuff play into it. Ever think about running a 15x7 up front and a 15x8 in the rear? Also if you have any pics of your truck,... that might help. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823 Last edited by lolife99; 01-09-2009 at 10:56 PM.

01-09-2009, 11:39 PM	#3
CG BlahBlahBlah Join Date: Feb 2002 Location: Wa. Posts: 20,136	Re: Backspacing Ive got the same issue going...check out this thread. http://67-72chevytrucks.com/vboard/s...d.php?t=322718

01-10-2009, 12:45 AM	#4
LEEVON Moderator Join Date: Jul 2006 Location: Ozark, MO Posts: 4,919	Re: Backspacing Here's mine, 15x8 and the standard 4.5" backspacing. They don't stick out or anything, look great but I want something bigger. For sale (less tires) for $500 plus shipping. __________________ '86 GMC C30 Crew ~ '86 C20 Crew ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '74K10 ~ '71 Cheyenne swb ~'50 3100 bagged ~ '80 Wife ~ Late model kids Last edited by LEEVON; 01-10-2009 at 12:46 AM.

01-10-2009, 01:05 AM	#5
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,717	Re: Backspacing Man Leevon,... that thing is SWEET! __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

01-10-2009, 01:08 AM	#6
LEEVON Moderator Join Date: Jul 2006 Location: Ozark, MO Posts: 4,919	Re: Backspacing Thanks lolife, I didn't mean to jack the thread...his truck could look like mine with these very wheels on it though my truck is actually a 10 footer, it's sporting 12 year old paint. ps-I saw your new shorty, it's sweet. I'll have to stop by sometime when I'm up that way. __________________ '86 GMC C30 Crew ~ '86 C20 Crew ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '74K10 ~ '71 Cheyenne swb ~'50 3100 bagged ~ '80 Wife ~ Late model kids Last edited by LEEVON; 01-10-2009 at 01:10 AM.

01-10-2009, 10:26 AM	#8
Hawker7 Registered User Join Date: Jan 2008 Location: Raleigh, NC Posts: 321	Re: Backspacing from reading some other posts it seems some people say 275's will rub up front, while others say they don't. Anyone running 275/60/15's on 15x8 with 4.5 backspacing all around???

01-10-2009, 01:33 PM	#11
70cst Senior Member Join Date: Feb 2001 Location: New Madison, Ohio Posts: 21,377	Re: Backspacing I have a 2"/4" drop with spindles (disc. brakes) and I ran into rubbing issues on the front wheels with 8/15 GM Ralleys. I bought 8/16" TT II's with the back spacing and I forsee no issues. JFYI. __________________ A husband can be right...or...A husband can be happy. 67-72 Chevy and GMC Trucks...The Classic Truck for the Classic Folk. 1970 CST Two tone green, 402BB, 400 Automatic, Tach, Buckets, AC, AM-FM, Tilt, GM CB, GM 8 Tract, LWB, etc JOHN 17:3...The better side of "LIFE" Remember: Everyday is a good day...Some are just gooder!

01-10-2009, 01:37 PM	#13
CG BlahBlahBlah Join Date: Feb 2002 Location: Wa. Posts: 20,136	Re: Backspacing You might check out this other thread I had going also. Check out seetens truck http://67-72chevytrucks.com/vboard/s...d.php?t=285491

01-10-2009, 01:39 PM	#14
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,717	Re: Backspacing Yes,... I've had a 275/60 on a stock height truck. Lowered trucks will be different. Search in the suspension section about wheels rubbing the lower control arms. It's been posted a bunch. Most people buy their wheels and then lower the truck to find out they don't work. If you're going to stay at stock height,... Leevon has the wheels for you! __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

01-10-2009, 06:44 PM	#17
LEEVON Moderator Join Date: Jul 2006 Location: Ozark, MO Posts: 4,919	Re: Backspacing I'm running 3" DJM lower control arms, stock spindles which would explain why I don't have any issues. It's been so long since I lowered it and put those wheels on...clearance might have been the reason I went with the LCA's instead of spindles. If I remember correctly, there is some light trimming to do on the drop spindles with 15x8 on 4.5" backspacing. I wouldn't want to start grinding on brand new spindles. But my setup works fine, Hawker I sent you a PM with the wheel pics. __________________ '86 GMC C30 Crew ~ '86 C20 Crew ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '74K10 ~ '71 Cheyenne swb ~'50 3100 bagged ~ '80 Wife ~ Late model kids

01-10-2009, 07:52 PM	#18
CG BlahBlahBlah Join Date: Feb 2002 Location: Wa. Posts: 20,136	Re: Backspacing LEEVON those tires on your truck are 275 60 15's?

01-11-2009, 01:31 PM	#19
Hawker7 Registered User Join Date: Jan 2008 Location: Raleigh, NC Posts: 321	Re: Backspacing what is the factory backspacing?

01-11-2009, 03:35 PM	#21
Hawker7 Registered User Join Date: Jan 2008 Location: Raleigh, NC Posts: 321	Re: Backspacing ok, so now will 255/60's work up front with the 4.5 backspacing and 275/60's out back? Is it the tire that rubs, or the wheel?



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