1972 20" Rim Back Spacing - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dhpenner · 04-21-2011, 09:49 PM

Im sure the answer is out there somewhere.... but after a couple hours of searching, im throwing in the towel

.

Im looking at buying some Boss 335 20" rims and want to know what the correct back spacing and width should be, front and back. I was thinking 20x8 up front and 20x10 in the back. My truck is a 72 SWB C10 with a 4/6 drop.

Thanks for your help in advance.

If you feel like leaving a smart a** reply or telling me to google it... please just private message me.

**lolife99** · 04-21-2011, 09:59 PM

5" bs on the 8's up front.
5.5" bs on the 10's for the rear.
Do they actually come in 20x8?
Or is it 20x8.5?

**lolife99** · 04-21-2011, 10:00 PM

I'm also assuming you''ll never bag it.
I'm also assuming you have the original 72 rearend.
(not a converted 67-69 narrower rearend)

**lolife99** · 04-21-2011, 10:02 PM

Do you have an adjustable track bar to re-center the rearend?
This is important when buying wheels.

dhpenner · 04-21-2011, 10:16 PM

Thank you Thank you Thank you! I had it bagged and didnt like it so i wont be going back to that. I have the CPP adjustable track bar so that shouldnt be a problem. Will the rims still fit if they are 8.5?

dhpenner · 04-21-2011, 10:24 PM

Would the B.S. change if i went with 19's?

fastwillie 696969 · 04-21-2011, 10:43 PM

i wouldnt go no more than 5 inch back space ,i would measure it out see how much you can go up to on back space, i had 20 inch wheels that had 3 inch back space ft and rear .275 40 20

gringoloco · 04-21-2011, 11:14 PM

Quote:

Originally Posted by lolife99

...5" bs on the 8's up front.
5.5" bs on the 10's for the rear...

Right on the money.

Quote:

Originally Posted by dhpenner

...Will the rims still fit if they are 8.5?...

Shoot for 5.25" BS on an 8.5" wheel on the front.

Quote:

Originally Posted by dhpenner

Would the B.S. change if i went with 19's?

No. This is a good size on these trucks, IMO, but you don't see many because of the lack of options in 19s...

travlinman · 04-22-2011, 12:04 AM

i just got my 335's today and i could only find them in 8.5..unless your going to have them custom made.

dhpenner · 04-22-2011, 01:49 AM

Could you throw some pictures up once you get them on?

hotrodhomi · 04-22-2011, 02:09 AM

we need pics.

**lolife99** · 04-22-2011, 11:06 AM

Quote:

Originally Posted by dhpenner

Will the rims still fit if they are 8.5?

I personally would go with a 5.5" BS on a 8.5" rim up front.
(I'm not sure what the Boss wheels have for "available" backspacing).

Here's a picture of 72BlckButy's truck.
The front wheels are 20x8.5 with a 5.5" backspace.
This is the perfect fit, for his 4.5/6 static dropped truck.

**lolife99** · 04-22-2011, 11:11 AM

Quote:

Originally Posted by fastwillie 696969

i wouldnt go no more than 5 inch back space ,i would measure it out see how much you can go up to on back space, i had 20 inch wheels that had 3 inch back space ft and rear .275 40 20

I couldn't disagree more.
But,... this is why I tell everyone to measure their own truck for their own wheels.
The OP ask for specific numbers,... and not to be told anything else.
(ie use search or Google, etc)
A 3" bs on a 6" wide rim will fit under the fenders.
A 3" bs on an 8"-10" rim will most likely rub on a static dropped truck.

I still stand by my "measure your own truck" statement.
There are too many varibles in these old trucks.

big_al_71 · 04-22-2011, 11:30 AM

Here is a pict of my 20x10 rear wheels with a 5.5 bs..

**Classic Heartbeat** · 04-22-2011, 12:51 PM

One thing that I don't see in some of the responces is the year. Rear ends from 67-69 are narrower than the 70-72. So what works for a 70-72 will not necessarely work for a 67-69. WES

**lolife99** · 04-22-2011, 01:03 PM

Quote:

Originally Posted by Classic Heartbeat

One thing that I don't see in some of the responces is the year. Rear ends from 67-69 are narrower than the 70-72. So what works for a 70-72 will not necessarely work for a 67-69. WES

Correct!
Sometimes trying to get all the info out of the OP is like "pulling teeth".
I normally ask all those questions, of the OP, but sometimes I never get a reply back.
That's why I said:
"I'm also assuming you have the original 72 rearend.
(not a converted 67-69 narrower rearend)"

dhpenner · 04-22-2011, 02:11 PM

Quote:

Originally Posted by lolife99

Correct!
Sometimes trying to get all the info out of the OP is like "pulling teeth".
I normally ask all those questions, of the OP, but sometimes I never get a reply back.
That's why I said:
"I'm also assuming you have the original 72 rearend.
(not a converted 67-69 narrower rearend)"

It is a 1972 Rearend, 4-6 static drop, CPP Adjustable track bar, I want 20x10 in the back (unless i could go wider... Can you go any wider?) and 20x8/8.5 in the front. I understand there is a lot of variances with these trucks but Im just looking to educate myself a little before I go to the tire shop. I dont want my tires to rub on the body, but i want to keep the wheels out as far as i can

dhpenner · 04-22-2011, 02:13 PM

Quote:

Originally Posted by big_al_71

Here is a pict of my 20x10 rear wheels with a 5.5 bs..

That is EXACTLY what im looking for. What is the B.S. and rim size on the front?

travlinman · 04-22-2011, 09:34 PM

if u look at dnd1978's build he puts the 335 on is truck (which made me buy mine) and as far as i know they only come in the 8.5.

http://67-72chevytrucks.com/vboard/s...d.php?t=452840

dhpenner · 04-24-2011, 01:44 AM

I have a line on rims off a 2006 corvette Z06, 18x8.5(front), 19x10(rear). will these fit? i think the back spacing will be way off. let me know if you or someone you know made it work. thanks

**lolife99** · 04-24-2011, 06:05 AM

Wrong bolt pattern.
They might work with spacers to correct the backspacing issues and incorrect bolt pattern.
I would price tires before you buy them also.
Posted via Mobile Device

dhpenner · 09-13-2011, 02:04 AM

Drat... Turns out you can only get the boss 335 rims in an 8.5 wide. What would the proper back spacing be for the front with a 8.5 wide, 20" rims?. Thanks
Posted via Mobile Device

Andy4639 · 09-13-2011, 07:10 AM

These are what is on my 71 which is the same as a 72.

The fronts don't scrub at all nothing.
20"x8.5"

Backs are 20"x10" I have a 3/8" spacer also to keep the tire from scrubbing the enner fender.
Sorry they through the rear boxes away before I thought to snap the pictures.

dhpenner · 09-13-2011, 08:55 PM

Sorry I mean 8.5 in the back... My bad. I can't wait until I buy rims so I can leave this headache behind.
Posted via Mobile Device

jim-bob · 01-15-2012, 04:45 PM

Quote:

Originally Posted by dhpenner

Sorry I mean 8.5 in the back... My bad. I can't wait until I buy rims so I can leave this headache behind.
Posted via Mobile Device

...So..what did you ever come up with..got pictures?

04-21-2011, 09:49 PM	#1
dhpenner Registered User Join Date: Feb 2010 Location: Canada Posts: 181	1972 20" Rim Back Spacing Im sure the answer is out there somewhere.... but after a couple hours of searching, im throwing in the towel . Im looking at buying some Boss 335 20" rims and want to know what the correct back spacing and width should be, front and back. I was thinking 20x8 up front and 20x10 in the back. My truck is a 72 SWB C10 with a 4/6 drop. Thanks for your help in advance. If you feel like leaving a smart a** reply or telling me to google it... please just private message me.

04-21-2011, 09:59 PM	#2
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,685	Re: 1972 20" Rim Back Spacing 5" bs on the 8's up front. 5.5" bs on the 10's for the rear. Do they actually come in 20x8? Or is it 20x8.5? __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

04-21-2011, 10:00 PM	#3
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,685	Re: 1972 20" Rim Back Spacing I'm also assuming you''ll never bag it. I'm also assuming you have the original 72 rearend. (not a converted 67-69 narrower rearend) __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

04-21-2011, 10:02 PM	#4
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,685	Re: 1972 20" Rim Back Spacing Do you have an adjustable track bar to re-center the rearend? This is important when buying wheels. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

04-21-2011, 10:16 PM	#5
dhpenner Registered User Join Date: Feb 2010 Location: Canada Posts: 181	Re: 1972 20" Rim Back Spacing Thank you Thank you Thank you! I had it bagged and didnt like it so i wont be going back to that. I have the CPP adjustable track bar so that shouldnt be a problem. Will the rims still fit if they are 8.5?

04-21-2011, 10:24 PM	#6
dhpenner Registered User Join Date: Feb 2010 Location: Canada Posts: 181	Re: 1972 20" Rim Back Spacing Would the B.S. change if i went with 19's?

04-21-2011, 10:43 PM	#7
fastwillie 696969 ~Rest In Peace~ Join Date: May 2005 Location: CALIFORNIA NOR CAL Posts: 9,707	Re: 1972 20" Rim Back Spacing i wouldnt go no more than 5 inch back space ,i would measure it out see how much you can go up to on back space, i had 20 inch wheels that had 3 inch back space ft and rear .275 40 20 __________________ is it fast ? it has a lighting bolt donut? B___H please, I can remove 90% of your so called "beauty" with a kleenex

04-22-2011, 12:04 AM	#9
travlinman Registered User Join Date: Feb 2009 Location: stockton ca. Posts: 502	Re: 1972 20" Rim Back Spacing i just got my 335's today and i could only find them in 8.5..unless your going to have them custom made. __________________ 94 ls swap silverado 65 Pontiac 78 c30 crew cab dually (parted and gone) 82 c30 crew cab dually ( now building ) 91 r30 crew cab dually (parted and gone) 69 swb-sold 71 lab sold all in progress......__ ..........._______ \|__\__ ..........\|__(O)______(O)] ........................

04-22-2011, 01:49 AM	#10
dhpenner Registered User Join Date: Feb 2010 Location: Canada Posts: 181	Re: 1972 20" Rim Back Spacing Could you throw some pictures up once you get them on?

04-22-2011, 02:09 AM	#11
hotrodhomi Registered User Join Date: Apr 2004 Location: Sacramento Posts: 3,737	Re: 1972 20" Rim Back Spacing we need pics. __________________ '72 2wd blazer, bagged w/ watts link & EDC '72 C10 "Lowered Farm Truck" STOLEN 5-18-11 '66 impala ht Last edited by hotrodhomi; 04-22-2011 at 02:09 AM.

04-22-2011, 11:30 AM	#14
big_al_71 Registered User Join Date: Jun 2008 Location: South Florida Posts: 11,375	Re: 1972 20" Rim Back Spacing Here is a pict of my 20x10 rear wheels with a 5.5 bs.. Attached Images __________________ Get your facts first, and then you can distort them as much as you please!!!!!. Sylvester's build thread >>>http://67-72chevytrucks.com/vboard/s...ht=big+rebuild

04-22-2011, 12:51 PM	#15
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,770	Re: 1972 20" Rim Back Spacing One thing that I don't see in some of the responces is the year. Rear ends from 67-69 are narrower than the 70-72. So what works for a 70-72 will not necessarely work for a 67-69. WES __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

04-22-2011, 09:34 PM	#19
travlinman Registered User Join Date: Feb 2009 Location: stockton ca. Posts: 502	Re: 1972 20" Rim Back Spacing if u look at dnd1978's build he puts the 335 on is truck (which made me buy mine) and as far as i know they only come in the 8.5. http://67-72chevytrucks.com/vboard/s...d.php?t=452840 __________________ 94 ls swap silverado 65 Pontiac 78 c30 crew cab dually (parted and gone) 82 c30 crew cab dually ( now building ) 91 r30 crew cab dually (parted and gone) 69 swb-sold 71 lab sold all in progress......__ ..........._______ \|__\__ ..........\|__(O)______(O)] ........................

04-24-2011, 01:44 AM	#20
dhpenner Registered User Join Date: Feb 2010 Location: Canada Posts: 181	Re: 1972 20" Rim Back Spacing I have a line on rims off a 2006 corvette Z06, 18x8.5(front), 19x10(rear). will these fit? i think the back spacing will be way off. let me know if you or someone you know made it work. thanks

04-24-2011, 06:05 AM	#21
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,685	Re: 1972 20" Rim Back Spacing Wrong bolt pattern. They might work with spacers to correct the backspacing issues and incorrect bolt pattern. I would price tires before you buy them also. Posted via Mobile Device __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823



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09-13-2011, 02:04 AM	#22
dhpenner Registered User Join Date: Feb 2010 Location: Canada Posts: 181	Re: 1972 20" Rim Back Spacing Drat... Turns out you can only get the boss 335 rims in an 8.5 wide. What would the proper back spacing be for the front with a 8.5 wide, 20" rims?. Thanks Posted via Mobile Device

09-13-2011, 07:10 AM	#23
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: 1972 20" Rim Back Spacing These are what is on my 71 which is the same as a 72. The fronts don't scrub at all nothing. 20"x8.5" Backs are 20"x10" I have a 3/8" spacer also to keep the tire from scrubbing the enner fender. Sorry they through the rear boxes away before I thought to snap the pictures. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

09-13-2011, 08:55 PM	#24
dhpenner Registered User Join Date: Feb 2010 Location: Canada Posts: 181	Re: 1972 20" Rim Back Spacing Sorry I mean 8.5 in the back... My bad. I can't wait until I buy rims so I can leave this headache behind. Posted via Mobile Device

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