Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.
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steved
- GTX (RS)
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2000 Nissan Xterra
2016 Fiesta ST
other stuff
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by steved » Fri Feb 19, 2010 8:30 pm
OH DAAAAAAYM...when I get the cash, or get tired of my cop rallyes...
sjd
1971 GTX, GY9 Tawny Gold.
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pats71
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by pats71 » Mon Feb 22, 2010 3:03 pm
I'll probably be getting a set of 15x10 magnum wheels for the rear and 15x7 in the front from specialty since their prices look to be the best.
Now is anyone running this big of a rim in the back of the 71' b bodies? The tires I'll be using are BFGoodrich 285/75/SR15. I need to know what backspacing you guys are using so I don't choose the wrong ones.
1971 Plymouth Roadrunner
383/4 speed/Air Conditioning

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471Magnum
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by 471Magnum » Mon Feb 22, 2010 4:07 pm
pats71' wrote:I'll probably be getting a set of 15x10 magnum wheels for the rear and 15x7 in the front from specialty since their prices look to be the best.
Now is anyone running this big of a rim in the back of the 71' b bodies? The tires I'll be using are BFGoodrich 285/75/SR15. I need to know what backspacing you guys are using so I don't choose the wrong ones.
A 285-75-15 is a monsterously tall tire. Almost 32 inches. That belongs on a truck, not a muscle car. You should expect clearance problems. Also, that much height will turn your car into a slug off the line unless you're running 4.10s.
28" is the max most people run. Most common size is a 275-60-15. That fits nice on an 8" rim.
Stock height would have been about 26".
-Jim
"I can fix it... my old man is a television repairman... he's got the
ULTIMATE set of tools... I can fix it."

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pats71
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by pats71 » Mon Feb 22, 2010 6:05 pm
I may be wrong on the size. I know for sure it is a 285 but it may be 70 or 65. Dad's bud who gave me these tires had the same size in the back of his 69' charger with 15x10 wheels. I think the rear wheel wells are larger in the 71-74 than they are in earlier b bodies.
1971 Plymouth Roadrunner
383/4 speed/Air Conditioning

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NOrrTH
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by NOrrTH » Tue Feb 23, 2010 3:03 pm
From threads I've read on this forum and Moparts, the largest tire apparently confirmed is 295 on an 8inch rim with 4.5 inch backspacing (cant recall the series).
I'll find out for sure in the spring. I guess the tire shops have no way of measuring these things accurately and make you buy a wheel and tire and hope they fit? If thats the case its pretty sad they dont have some system of figuring it out.
'71 GTX N96
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471Magnum
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by 471Magnum » Tue Feb 23, 2010 3:16 pm
NOrrTH wrote:From threads I've read on this forum and Moparts, the largest tire apparently confirmed is 295 on an 8inch rim with 4.5 inch backspacing (cant recall the series).
I'll find out for sure in the spring. I guess the tire shops have no way of measuring these things accurately and make you buy a wheel and tire and hope they fit? If thats the case its pretty sad they dont have some system of figuring it out.
That would be a 295-50-15. I believe Firestone still makes that size.
That's a 26.6" tall versus almost 32"
-Jim
"I can fix it... my old man is a television repairman... he's got the
ULTIMATE set of tools... I can fix it."

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71srt
- Satellite Coupe (RL)
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by 71srt » Mon Mar 15, 2010 7:36 pm

- in progress
- P1010428.JPG (170.23 KiB) Viewed 14487 times
some wheels from a magnum.
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gionni
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by gionni » Mon Jun 07, 2010 5:10 am
my RR has 19x8 on 245/40-19 and 20x10 on 275/40-20, all with offset 7mm...and no body mods...

- RunnerHomepage4.jpg (363.89 KiB) Viewed 14440 times
"PRO RUNNER" 1971 Road Runner Pro Touring (GY9 Tawny Gold)
AERODYNAMIC IS FOR PEOPLE THAT CAN'T BUILD ENGINES!
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NOrrTH
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by NOrrTH » Fri Jul 09, 2010 10:19 pm
That car must really turn heads. I can see the young guys going nuts over it. "WTF is that!"

'71 GTX N96
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BigBlock
- Satellite Sebring (RH)
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by BigBlock » Mon Feb 28, 2011 10:06 pm
pats71' wrote:I'll probably be getting a set of 15x10 magnum wheels for the rear and 15x7 in the front from specialty since their prices look to be the best.
Now is anyone running this big of a rim in the back of the 71' b bodies? The tires I'll be using are BFGoodrich 285/75/SR15. I need to know what backspacing you guys are using so I don't choose the wrong ones.
I am running 295/50/15's on my rear. 4.5" backspacing on 15x10's with room to spare. Actually, I think a 5" backspacing would look better. it would tuck them in nicely.

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BigBlock
- Satellite Sebring (RH)
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by BigBlock » Mon Feb 28, 2011 10:09 pm
[/quote]
That would be a 295-50-15. I believe Firestone still makes that size.
That's a 26.6" tall versus almost 32"[/quote]
BFG makes one in their Radial T/A. It's what I'm running. They are around $200 a tire.
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gionni
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by gionni » Tue Mar 01, 2011 6:50 am
rmj wrote:Back from the dead! This is a REALLY old pic. 18x8 and 20x8 Centerlines. I don't remember the front tire size, but the rear is 265/50/20 BFG KDW 2's .
Gionni, back before your airride, did you have your springs moved in to hold the 20x10's?
These are pretty close to the springs now.
It has a 380 hp crate motor with march serpentine and sanden a/c. Factory metallic green interior.
Fixing to remedy the interior with something like Gionnis.
Gionni, was it hard covering your dash in leather? (I'm thinking ofdoing my door panels and console too.)
Thanks
Richard Milne

wow, nice satellite man! do you have more pics?
no, i never moved the springs in...the 20x10 mit 7mm offset fits without mods on springs or on body!
the covering of the dash in leather was a hard job...and it needs streching leather..like the orginal material of factory cars. mine is from BMW...
"PRO RUNNER" 1971 Road Runner Pro Touring (GY9 Tawny Gold)
AERODYNAMIC IS FOR PEOPLE THAT CAN'T BUILD ENGINES!