Max Rear Tire Size

Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.

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72RARBIRD

Max Rear Tire Size

Post by 72RARBIRD » Sat Oct 09, 2004 9:59 pm

Any recommendations of max tire/rim combinations. Has anyone mounted a 275/60/15 on a 15X8, 4-1/2 backspaced rim? I'm concerned with the increased section width of the 15X8 versus 15X7.

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Rear Tire size OK

Post by CtownRunner » Sun Oct 10, 2004 7:17 am

I have 275/60 x15 on Mirada wheels that are 4.5in backspaced and 8in Wide, they fit very well. I have at least an inch to clear the rear spings and more to the inner edge of the wheel well lip.

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Chris

72RARBIRD

Post by 72RARBIRD » Sun Oct 10, 2004 8:01 am

Chris,

Thanks for info. What are you running on the front?

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Front Tires

Post by CtownRunner » Sun Oct 10, 2004 8:08 pm

Fronts are 235/70x15 on same wheels. Keeps the rolling diameter the same. Almost went with this on all 4 but the 60's in back give this style car nicer lines. I have air shocks in back (they came on the car) for just a little lift but not needed for the tires to fit. Just a little nose down attitude and T bar adjustment. I think I will play with a little less air in the rear soon.

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Dave
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Post by Dave » Mon Oct 11, 2004 8:28 am

FWIW, I'm running a 4.75" backspace on an 8" rim. That perfectly centers the rim in the wheelhouse. Here are a couple pictures of the "test fit" of the Road Runner's rims with the 295-50-15's on the Sebring Plus

Image
Image

It's dead on 3/4" clearance to the spring.
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Post by road chicken » Tue Oct 12, 2004 11:17 am

I run 255/60/15's on 15X8 ( 0 offset) on all four corners. I know I can get a 295 on the rear, as we have seen- but the 255 is about the biggest for the front and not have interference when the wheels are fully turned.
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68 383, Street Demon 750, RPM top end,484/284/108 poo poo cam "-5 spd 4:10 SG, 4whl disk, Helwig Anti-Sway, Poly bushings,Firm Feel Box, HD Linkage, 1" t-bars, 7 leafs Springs

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Post by Dave » Tue Oct 12, 2004 2:16 pm

Ah cool. My "math" said I might have a slight rub at full turn on the fronts with the 245-60's on the 15x7's, but I wasn't 100% sure about that. I'm guessing that if your 255's clear, my 245's should be fine. That's great news! :)
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Post by road chicken » Tue Oct 12, 2004 10:04 pm

Ya I run a 1.00" T bar up front so the suspension isn't squishing around. I have @ 1/2" clearance to the sheet metal as the wheel goes through it's arc and @ 5/8" from the frame at lock. The 245's will be no problem
4th generation B bodys- there is no substitute.
68 383, Street Demon 750, RPM top end,484/284/108 poo poo cam "-5 spd 4:10 SG, 4whl disk, Helwig Anti-Sway, Poly bushings,Firm Feel Box, HD Linkage, 1" t-bars, 7 leafs Springs

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