Backspace for 15" wheel? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

C10Slim · 11-07-2009, 07:22 PM

Will 15x8 6x5.5 4.25 Backspace work on a 66? Want to order my smoothies next week.

protrash64 · 11-07-2009, 09:50 PM

I believe so...depends on how big a tire and how low the truck sits. I think the truck Rallys have 4.25'' BS also......I'm running a 295/50/15 on the rear of my burb on Rally rims.

*lakeroadster* · 11-08-2009, 08:02 AM

How big of a tire are you going to use?

Fleetside or stepside?

**62 Longbed** · 11-09-2009, 02:18 AM

I agree with protrash64 ...depends on how big a tire and how low the truck sits. I also believe the truck Rallys have 4.25'' BS .....I'm running a 305/50/15 on the rear of my 62 with on Rally rims.

Slow Build · 11-09-2009, 03:28 AM

I measured my 6 lug rally spare the other day. I thought I came up with 3.75" backspacing. I'll have to double check tomorrow.

**62 Longbed** · 11-09-2009, 04:04 AM

I'll do the same and measure mine also ...

C10Slim · 11-09-2009, 11:00 AM

I have a 5 - 7 drop and was planning on trying to run something like a 235/70/15 or so.

Guy in Classic Truck mag has the same setup and ran Coker Classic bias-ply WW, 7.60-15 which is what I am trying to translate too.

*lakeroadster* · 11-09-2009, 11:22 AM

Quote:

Originally Posted by Slow Build

I measured my 6 lug rally spare the other day. I thought I came up with 3.75" backspacing. I'll have to double check tomorrow.

Yep, I just measured the 6 lug truck rallies I had on my '65, they are 3-5/8" back spacing.

C10slim,

I ran stock truck rallies (3-5/8" b.s.) and P235/75R15 on the front, 31x10.5x15 on the rear, with no clearance issues.

Don't know if the 4-1/4" b.s. will give you any issues on the front or not. They won't be a problem on the rear.

Hope this helps.

**TR65** · 11-10-2009, 10:46 PM

Hey Slim,

I am running 6 lug 15X8 with a 4" backspace on my 65. I have to run 1/4" wafer spacers to clear the late model brake calipers, so that makes the real backspace 3-3/4". If you are running drums that shouldn't be a problem. I am running P235/75R15 tires, plenty of clearance for them.

TR

Slow Build · 11-10-2009, 11:28 PM

I measured again today. That's what I come up with, 3.75".

C10Slim · 11-11-2009, 04:06 PM

Awesome guys exactly what I needed!!

TR65 - I have converted to disc also. You got the look I am after except I am going to run white walls.

protrash64 · 11-11-2009, 10:10 PM

The difference in backspace must be between 6-lug and 5-lug. My Rallys are 5 lug....4.25'' bs.

I also have no clearance issues with disc brakes, dropped spindles, and bags.

**TR65** · 11-11-2009, 10:59 PM

Hey Slim,

I really like the smoothy look as well.

Hey Pro,

It may be the position of the drop well that causes the interference so it probably depends on the particular wheel design.

TR

C10Slim · 11-11-2009, 11:15 PM

This is the look I am going for although the new cragar wheel with a chrome spider cap is starting to grow on me also.

11-07-2009, 07:22 PM	#1
C10Slim Registered User Join Date: Jul 2009 Location: Needville, TX Posts: 283	Backspace for 15" wheel? Will 15x8 6x5.5 4.25 Backspace work on a 66? Want to order my smoothies next week.

11-07-2009, 09:50 PM	#2
protrash64 Resistance is Futile Join Date: Dec 2006 Location: Mesa,Arizona Posts: 3,519	Re: Backspace for 15" wheel? I believe so...depends on how big a tire and how low the truck sits. I think the truck Rallys have 4.25'' BS also......I'm running a 295/50/15 on the rear of my burb on Rally rims. __________________ 64 CHEVY PICK-UP > http://67-72chevytrucks.com/vboard/s...otrash+re-hash 64 CARRYALL >http://67-72chevytrucks.com/vboard/s...=1964+suburban 66 LB >http://67-72chevytrucks.com/vboard/s...d.php?t=427852 STRENGTH/DETERMINATION/MERCILESS/FOREVER .......posted via stationary device Last edited by protrash64; 11-07-2009 at 09:51 PM.

11-08-2009, 08:02 AM	#3
lakeroadster Account Suspended Join Date: Sep 2009 Location: High Plains of Colorado Posts: 2,485	Re: Backspace for 15" wheel? How big of a tire are you going to use? Fleetside or stepside?

11-09-2009, 02:18 AM	#4
62 Longbed Senior Member Join Date: Nov 2008 Location: Gresham , Oregon Posts: 588	Re: Backspace for 15" wheel? I agree with protrash64 ...depends on how big a tire and how low the truck sits. I also believe the truck Rallys have 4.25'' BS .....I'm running a 305/50/15 on the rear of my 62 with on Rally rims. Attached Images Last edited by 62 Longbed; 11-09-2009 at 02:19 AM.

11-09-2009, 03:28 AM	#5
Slow Build Registered User Join Date: Sep 2009 Location: California Delta Posts: 2,163	Re: Backspace for 15" wheel? I measured my 6 lug rally spare the other day. I thought I came up with 3.75" backspacing. I'll have to double check tomorrow. __________________ Name: Rich Current Ride: 1964 C-10 Short Fleetside Daily Driver: 2005 GMC crew cab short fleetside /2001 Chevy Tahoe Past GM Trucks: 1959 GMC short stepside 1968 GMC short stepside-4x4 1973 Chevy short stepside 1989 Chevy short fleetside-reg cab 1993 Chevy short fleetside-Xcab 2002 Chevy short fleetside-Xcab Save the dinosaurs, use synthetic oil.

11-09-2009, 04:04 AM	#6
62 Longbed Senior Member Join Date: Nov 2008 Location: Gresham , Oregon Posts: 588	Re: Backspace for 15" wheel? I'll do the same and measure mine also ...

11-09-2009, 11:00 AM	#7
C10Slim Registered User Join Date: Jul 2009 Location: Needville, TX Posts: 283	Re: Backspace for 15" wheel? I have a 5 - 7 drop and was planning on trying to run something like a 235/70/15 or so. Guy in Classic Truck mag has the same setup and ran Coker Classic bias-ply WW, 7.60-15 which is what I am trying to translate too.

11-10-2009, 10:46 PM	#9
TR65 Senior Member Join Date: Nov 2007 Location: Greenville, SC Posts: 873	Re: Backspace for 15" wheel? Hey Slim, I am running 6 lug 15X8 with a 4" backspace on my 65. I have to run 1/4" wafer spacers to clear the late model brake calipers, so that makes the real backspace 3-3/4". If you are running drums that shouldn't be a problem. I am running P235/75R15 tires, plenty of clearance for them. TR Attached Images __________________ 1965 C10 SWB Fleet Two owner LS2 Swap Thread http://67-72chevytrucks.com/vboard/s...d.php?t=413880

11-10-2009, 11:28 PM	#10
Slow Build Registered User Join Date: Sep 2009 Location: California Delta Posts: 2,163	Re: Backspace for 15" wheel? I measured again today. That's what I come up with, 3.75". __________________ Name: Rich Current Ride: 1964 C-10 Short Fleetside Daily Driver: 2005 GMC crew cab short fleetside /2001 Chevy Tahoe Past GM Trucks: 1959 GMC short stepside 1968 GMC short stepside-4x4 1973 Chevy short stepside 1989 Chevy short fleetside-reg cab 1993 Chevy short fleetside-Xcab 2002 Chevy short fleetside-Xcab Save the dinosaurs, use synthetic oil.

11-11-2009, 04:06 PM	#11
C10Slim Registered User Join Date: Jul 2009 Location: Needville, TX Posts: 283	Re: Backspace for 15" wheel? Awesome guys exactly what I needed!! TR65 - I have converted to disc also. You got the look I am after except I am going to run white walls.

11-11-2009, 10:10 PM	#12
protrash64 Resistance is Futile Join Date: Dec 2006 Location: Mesa,Arizona Posts: 3,519	Re: Backspace for 15" wheel? The difference in backspace must be between 6-lug and 5-lug. My Rallys are 5 lug....4.25'' bs. I also have no clearance issues with disc brakes, dropped spindles, and bags. __________________ 64 CHEVY PICK-UP > http://67-72chevytrucks.com/vboard/s...otrash+re-hash 64 CARRYALL >http://67-72chevytrucks.com/vboard/s...=1964+suburban 66 LB >http://67-72chevytrucks.com/vboard/s...d.php?t=427852 STRENGTH/DETERMINATION/MERCILESS/FOREVER .......posted via stationary device

11-11-2009, 10:59 PM	#13
TR65 Senior Member Join Date: Nov 2007 Location: Greenville, SC Posts: 873	Re: Backspace for 15" wheel? Hey Slim, I really like the smoothy look as well. Hey Pro, It may be the position of the drop well that causes the interference so it probably depends on the particular wheel design. TR __________________ 1965 C10 SWB Fleet Two owner LS2 Swap Thread http://67-72chevytrucks.com/vboard/s...d.php?t=413880

11-11-2009, 11:15 PM	#14
C10Slim Registered User Join Date: Jul 2009 Location: Needville, TX Posts: 283	Re: Backspace for 15" wheel? This is the look I am going for although the new cragar wheel with a chrome spider cap is starting to grow on me also. Attached Images



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