66-67 Plymouth Backspacing for 8" wheel

[robinsonwr]

OK guys, I want to order my wheels from Stockton by Monday. My question is what is the best backspacing for a 8" wheel with 255 60 15 or 275 60 15 tires mounted without modifying the car? I saw a post that 4 3/4 backspacing will work without modification with a 275 60 15. Understand that I will be running a tire with an inch smaller section width than the 275 60 15 on a 14" wheel. Additional tire information below. I appreciate your help in advance on helping me make this decision, thanks.

275/55 14
Wheel Diameter 14 in.
Sidewall Style Solid white letters
Tire Construction Bias-ply
Directional No
Tire Diameter 26.10 in.
Section Width 10.10 in.
Tread Width 8.50 in.
Minimum Recommended Wheel Width 6.00 in.
Maximum Recommended Wheel Width 8.00 in.

How it compares to Tire Size 255/60-15
Wheel Diameter 15 in.
Sidewall Style Solid white letters
Tire Construction Radial
Directional No
Tire Diameter 27.00 in.
Section Width 10.24 in.
Tread Width 8.20 in.
Minimum Recommended Wheel Width 7.00 in.
Maximum Recommended Wheel Width 9.00 in.

 

[terzmo]

255 by 60 by 15 tire will work on a stock 7 inch rim. 275 will need a modified backspace. I HAD a 29 inch tall tire on My 67 gtx and it rubbed the front of the rear qtr. 26 inch tall has plenty of room...27 will work...28 is testing it

 

[67 coronet]

if a completely stock setup,then a 4.5 inch back space should center the 255 60 15 good.if anything is changed back there,then get one of the measurement devises percys makes.they are sold by summit and jegs.

 

[robinsonwr]

255 by 60 by 15 tire will work on a stock 7 inch rim. 275 will need a modified backspace. I HAD a 29 inch tall tire on My 67 gtx and it rubbed the front of the rear qtr. 26 inch tall has plenty of room...27 will work...28 is testing it

Stock 7" wheels have a 4 1/4 backspace? I will be buying a 14 X 8 wheel to be at maximum wheel size for the 275 55 14 tire I want to run. The 14" tire is very comparable to the 255 60 15 just an inch shorter. I am trying to get the wheel/tire combo centered in the tub opening.

 

[robinsonwr]

if a completely stock setup,then a 4.5 inch back space should center the 255 60 15 good.if anything is changed back there,then get one of the measurement devises percys makes.they are sold by summit and jegs.

That 4.5 backspacing is for an 8" wheel?

 

[67 coronet]

That 4.5 backspacing is for an 8" wheel?

ya,8" wheel.that is what i ran on my 67 coronet before mods.255 60 15,15x8 wheel,4.5" backspace.

 

[tirefryin-Bob]

8" wheels

OK guys, I want to order my wheels from Stockton by Monday. My question is what is the best backspacing for a 8" wheel with 255 60 15 or 275 60 15 tires mounted without modifying the car? I saw a post that 4 3/4 backspacing will work without modification with a 275 60 15. Understand that I will be running a tire with an inch smaller section width than the 275 60 15 on a 14" wheel. Additional tire information below. I appreciate your help in advance on helping me make this decision, thanks.

275/55 14
Wheel Diameter 14 in.
Sidewall Style Solid white letters
Tire Construction Bias-ply
Directional No
Tire Diameter 26.10 in.
Section Width 10.10 in.
Tread Width 8.50 in.
Minimum Recommended Wheel Width 6.00 in.
Maximum Recommended Wheel Width 8.00 in.

How it compares to Tire Size 255/60-15
Wheel Diameter 15 in.
Sidewall Style Solid white letters
Tire Construction Radial
Directional No
Tire Diameter 27.00 in.
Section Width 10.24 in.
Tread Width 8.20 in.
Minimum Recommended Wheel Width 7.00 in.
Maximum Recommended Wheel Width 9.00 in.

On my 66' Satellite I use to run a 7" wheel on 275/60-15's, the back space was 4". The outer tire clearance was very close, it would rub on occasion in tight corners. I resolved this by installing SS springs.
8" wheel will need to be 4 1/2" back, leaving you with 3 1/2" outer space... You will need SS springs or large rear anti-roll bar... Also go with the skinner tire... I know - 66'-67' Plymouth's rear tire clearance's are a bitch..:3gears:

 

[robinsonwr]

I certainly appreciate your input it is duely noted.

 

[robinsonwr]

On my 66' Satellite I use to run a 7" wheel on 275/60-15's, the back space was 4". The outer tire clearance was very close, it would rub on occasion in tight corners. I resolved this by installing SS springs.
8" wheel will need to be 4 1/2" back, leaving you with 3 1/2" outer space... You will need SS springs or large rear anti-roll bar... Also go with the skinner tire... I know - 66'-67' Plymouth's rear tire clearance's are a bitch..:3gears:

Thank you for your input. What do you think about the 14" wheel/tire combo I am looking at? The tire is more comparable to a 255 60 15 than a 275 60 15. I think it will be cool to have some hook under a hubcap.

 

[Meep-Meep]

You really need 4.75" BS with an 8" wheel. I have a pair of 4.375" BS 8" wheels with 255 60 15 and they end up rubbing on the outside lip as you go over bumps or when the body shifts in cornering.

 

[robinsonwr]

Meep-Meep
So you really think the 4 3/4 backspacing will center the wheel/tire combo better in the wheel well? Oh, great job on those transmission lines that looks really sweet.

 

[ultramag870]

I am looking at same thing on my 69 GTX i was planning on getting 15x8 wheels with 4.5" backspacing so I would be ok to use this setup?

 

[robinsonwr]

I am looking at same thing on my 69 GTX i was planning on getting 15x8 wheels with 4.5" backspacing so I would be ok to use this setup?

The 68-70 b-bodies actually have more room for a larger tire and wheel combination. The 66-67 cars are extremely limited without modifications. check the forum and you will probably find just how much wheel and tire you can run. I think I remember 295 65 15 and 10" wheels being the largest without mods so a 255 60 15 want be a problem.

 

[popcop]

Ok, new here. So if I am running the 7x15" police wheel, what back space does that have, and or the widest tire I can run with out trimming anything? I want to keep the steel wheels? Any help will be greatly appreciated.
Thanks, Popcop