Simple tire size question...(i think)? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

wwotr · 06-04-2009, 12:55 PM

On my newly acquired 72 GMC, it came with 235/70 R-15 on the Front.
(see picture enclosed).
My initial reason for going a size smaller was the way the previous owner had cut the Springs, it seemed close to the Inner Fenderwell hitting the Top of the Tire and the Sidewall scrapping the Front Fender.

I asked my Tire guy and he said..............
"If you go with a 215/75/15 it would be about an inch thinner and the same height. If you go with a 205/75/15 it would be about 1.5 inch half thinner and a little shorter ".

But now I'm going with a 3"/4" Spring kit. So thats a mute point, but I do like the idea of a little thinner tire in Front and Bigger in back.

So my initial question is if I go with a Front Tire that is slightly "smaller" in Diameter, will it actually LOWER the Front End a little more, (no matter how small of an increment that might be)?

Roger

Longhorn Man · 06-04-2009, 03:28 PM

yes

PanelDeland · 06-04-2009, 07:19 PM

http://www.miata.net/garage/tirecalcold.html

http://www.dakota-truck.net/TIRECALC/

Some aids for tire selection.One has good visuals(the first I think)

wwotr · 06-04-2009, 07:48 PM

Panel Deland ,
That is exactly what I needed........... and MORE!

Thank you kind sir!!!

You RAWK!

Roger

Hottrucks · 06-04-2009, 08:15 PM

all I can say is I have 235/75/15 on the front of my truck with bags and a cupped lower..that tire is 29 1/2" tall and it's 1/4" from my inner FENDER and heater box..notice I siad fender not the inner slash those are gone and I can turn from stop to stop without hitting

tim21391 · 06-05-2009, 12:05 AM

i run 31x10.50/15s

68Stepbed · 06-05-2009, 11:31 AM

I have a 3.5/5 drop. I'm running 15x8 wheels all around with 255/60/15 front 275/60/15 rear tires without any rubbing issues. If you're going with a 3/4 spring kit, the tires you have should work fine.

Here's some shots of mine for comparison.

wwotr · 06-05-2009, 11:43 AM

68 Stepbed,
That is a BEAUTIFUL TRUCK!

I appreciate your input.
I'm thinking of going with the smaller 205/75/15 in Front.
The only reason is that I like the look/Heigth in front now,
(with the Front springs cut 5"). After I put in the 3" Springs in Front, I'm sure it will be higher than it is now.
I'd like to take that smaller 205/75/15 and put it on the Front to get the Front end as close to where it is NOW, as possible.
Roger

ChevLoRay · 06-05-2009, 11:52 AM

I have 245-60R15's in front and 275-60R15's in back. I have a 2.5/4.0 drop done with spindles (ECE) up front and springs out back. Front wheels are 8-inches wide and rears are 10 inches wide. Front offset is 4 inches while rear is 5 inches. The truck is a '69, so the rear end is about an inch narrower than your '72 rearend.

wwotr · 06-05-2009, 12:12 PM

Chevloray,

No offense to you, but your Truck is not what I'm wanting.
It (as is my Truck), is still too high in the back.
Here is my GMC the way it sits today and the picture of the Green C-10, is the perfect stance I'm looking for.
Now I realize I wont get that stance with just the Springs I'm having put on and that in the future I'll have to go to Drop Spindles in Front and maybe a C-Notch in the Rear.

Roger
----------------------------------------------------------------------

Quote:

Originally Posted by ChevLoRay

I have 245-60R15's in front and 275-60R15's in back. I have a 2.5/4.0 drop done with spindles (ECE) up front and springs out back. Front wheels are 8-inches wide and rears are 10 inches wide. Front offset is 4 inches while rear is 5 inches. The truck is a '69, so the rear end is about an inch narrower than your '72 rearend.

06-04-2009, 12:55 PM	#1
wwotr Registered User Join Date: Jan 2005 Location: Clearlake Oaks CA Posts: 1,716	Simple tire size question...(i think)? On my newly acquired 72 GMC, it came with 235/70 R-15 on the Front. (see picture enclosed). My initial reason for going a size smaller was the way the previous owner had cut the Springs, it seemed close to the Inner Fenderwell hitting the Top of the Tire and the Sidewall scrapping the Front Fender. I asked my Tire guy and he said.............. "If you go with a 215/75/15 it would be about an inch thinner and the same height. If you go with a 205/75/15 it would be about 1.5 inch half thinner and a little shorter ". But now I'm going with a 3"/4" Spring kit. So thats a mute point, but I do like the idea of a little thinner tire in Front and Bigger in back. So my initial question is if I go with a Front Tire that is slightly "smaller" in Diameter, will it actually LOWER the Front End a little more, (no matter how small of an increment that might be)? Roger Attached Images __________________ Hello members... I'd like you to know that I sold, my 72 GMC (Ratikle), back in November of 2011. I don't visit the site much anymore, but please feel free, to drop me a private message. RIP...."RATIKLE"

06-04-2009, 03:28 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Simple tire size question...(i think)? yes

06-04-2009, 07:19 PM	#3
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,992	Re: Simple tire size question...(i think)? http://www.miata.net/garage/tirecalcold.html http://www.dakota-truck.net/TIRECALC/ Some aids for tire selection.One has good visuals(the first I think) __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

06-04-2009, 07:48 PM	#4
wwotr Registered User Join Date: Jan 2005 Location: Clearlake Oaks CA Posts: 1,716	Re: Simple tire size question...(i think)? Panel Deland , That is exactly what I needed........... and MORE! Thank you kind sir!!! You RAWK! Roger __________________ Hello members... I'd like you to know that I sold, my 72 GMC (Ratikle), back in November of 2011. I don't visit the site much anymore, but please feel free, to drop me a private message. RIP...."RATIKLE"

06-04-2009, 08:15 PM	#5
Hottrucks Redefining LowBudget Join Date: Mar 2009 Location: lebanon Cow Hampshire Posts: 4,538	Re: Simple tire size question...(i think)? all I can say is I have 235/75/15 on the front of my truck with bags and a cupped lower..that tire is 29 1/2" tall and it's 1/4" from my inner FENDER and heater box..notice I siad fender not the inner slash those are gone and I can turn from stop to stop without hitting __________________ 1970 C10 CST fleetside 472 ....big dreams little cash... http://67-72chevytrucks.com/vboard/s...d.php?t=335721 SunShine Syndicate.. Mikes Sandwich Fair Run OCT 8th 2011 http://www.thesandwichfair.com/html/...auto_show.html

06-05-2009, 12:05 AM	#6
tim21391 Registered User Join Date: Jul 2007 Location: Salina, Kansas Posts: 1,998	Re: Simple tire size question...(i think)? i run 31x10.50/15s __________________ 1972 C-10...402/400..flowmaster 40 series 1967 Mustang 347 stroker/C-4 1966 Mustang 289/3-speed 2013 Mustang V6/6speed w/300 ponies I may be 23, but i sure do knows 67-72s are sexy! Its not MPG its smiles per gallon! build started 11/25/08 build thread: http://67-72chevytrucks.com/vboard/s....php?p=2993796

06-05-2009, 11:31 AM	#7
68Stepbed Registered User Join Date: Mar 2005 Location: 10-Uh-See Posts: 5,609	Re: Simple tire size question...(i think)? I have a 3.5/5 drop. I'm running 15x8 wheels all around with 255/60/15 front 275/60/15 rear tires without any rubbing issues. If you're going with a 3/4 spring kit, the tires you have should work fine. Here's some shots of mine for comparison. __________________ Matt 68 C10 stepside, LS1/700R4, TCI Engineering suspension system

06-05-2009, 11:43 AM	#8
wwotr Registered User Join Date: Jan 2005 Location: Clearlake Oaks CA Posts: 1,716	Re: Simple tire size question...(i think)? 68 Stepbed, That is a BEAUTIFUL TRUCK! I appreciate your input. I'm thinking of going with the smaller 205/75/15 in Front. The only reason is that I like the look/Heigth in front now, (with the Front springs cut 5"). After I put in the 3" Springs in Front, I'm sure it will be higher than it is now. I'd like to take that smaller 205/75/15 and put it on the Front to get the Front end as close to where it is NOW, as possible. Roger __________________ Hello members... I'd like you to know that I sold, my 72 GMC (Ratikle), back in November of 2011. I don't visit the site much anymore, but please feel free, to drop me a private message. RIP...."RATIKLE"

06-05-2009, 11:52 AM	#9
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: Simple tire size question...(i think)? I have 245-60R15's in front and 275-60R15's in back. I have a 2.5/4.0 drop done with spindles (ECE) up front and springs out back. Front wheels are 8-inches wide and rears are 10 inches wide. Front offset is 4 inches while rear is 5 inches. The truck is a '69, so the rear end is about an inch narrower than your '72 rearend. Attached Images __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

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