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#1
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Tire size/brand questions
I picked up a set a clean set of 15x7 Rally II wheels for my '70 TA. I was looking to get a set of radials for it and keep the JW wheels, and Polyglas tires for shows.
Even with the factory wheels, it looks like the TA could use a bit wider tire, especially in the back. What's the widest I could run (on a 15x7 wheel) and would you recommend staggered widths (a bit narrower up front)? I was originally just going to order a set of the ubiquitous BRG Radial T/A tires, but I was reading though a number of posts that complained about the RWL yellowing on the modern versions. So then I thought about getting a set of the Firestone Wide-Ovals. I'm assuming these will be more expensive than the BFGs, but I'm willing to pay the extra cost to avoid the yellowing. Any thoughts?
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Three times the sound peaks, falls back, peaks again. A throttling back to cruising speed, a dwindling grumble of thunder and...gone. The frogs take up where they left off. |
#2
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Really should NOT run wider than a 60 series tire on a 7 inch wide rim as the sidewall can roll MORE than it should. Factory 26 inch tall tire gives limited options. The BFG , Cobra, and the repro Firestone All don't balance well when you high speed balance them. A 15x8 rally might be what you want on the rear. Keep in mind these cars were built to sit slightly lower in the rear for a few reasons.
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#3
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Thanks Bruce. If I stay with the stock F60 size (not sure what that translates to in modern sizes) is there really no difference between the BFG and Firestones?
Is the G60 wider than the F60? I think I saw those on the Coker site. Sent from my iPhone using Tapatalk
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Three times the sound peaks, falls back, peaks again. A throttling back to cruising speed, a dwindling grumble of thunder and...gone. The frogs take up where they left off. |
#4
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I run 245/60-15s on the front and 275/60-15s on the rear.
Definitely not a stock look, but they fit fine.
__________________
"Those poor souls have made the fatal mistake of surrounding us. Now we can fire in any direction" 1970 Trans Am RAIII 4 speed 1971 Trans Am 5.3 LM7 1977 Trans Am W72 Y82 1987 Grand National |
#5
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I'd run a 235 or 245/60R15 on all 4 corners. Running a larger back tire on the same size wheel as the front doesn't look right in my opinion. They end up looking like balloons... throws off the balance of the car... If you are going to run a fatter tire in the rear.... buy a wider wheel for the rear..
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Current Pontiacs - 1973 Formula SD455 - #'s auto orig paint 1972 Trans Am - 4 speed orig paint 1974 Formula 400 - Ram Air automatic 1966 2+2 convertible - 421 4bbl automatic 1967 Grand Prix - 4 speed orig paint 1967 GTO - 4 speed orig paint 35k orig miles |
#6
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Racerboy, You can run 255/60R15's without any problems on all 4 corners of your TA. They mount very nicely on 15x7 wheels and are 27"+ tall, so about 1.5" to 2" taller than F60-15 Polyglas's. Here is my '71 Formula with 15x7 Honey's w/255/60R15 Radial TA's and 15x7 steelies with 255/60R15 Mickey Thompson's (which are 1/2" taller?).
Dennis |
The Following 2 Users Say Thank You to SD455DJ For This Useful Post: | ||
#7
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255/60 are the closest in height to the stock 225/70 tires & fit on a 15x7 wheel nicely... no ballooning or rolling of sidewalls.
check out the M/T st radials, they are a solid white letter & dont have the browning issue of BFG's from what ove seen. they are also a more modern tread than bfg with higher speed ratings... & cheaper too. |
#8
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Racerboy,
Here are some pixs of my '70 & '73. I'm running 245's on the front of the '70 and 255's on the back. Using the original JW's. The '73 I'm running 255's all around. I was running a 255 on the front of the '70, but had a slight rubbing problem. going to the 245 solved the problem. The '73 uses 15x7 rims with no rubbing issues. Hope this helps. Last edited by napster; 05-08-2021 at 11:34 AM. |
#9
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245 fit nicely and look correct. I have run 255s on the back in the past
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#10
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Quote:
Think you will find that the 255/60 are over 1 inch taller. |
#11
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Just to clarify stock size on a 1970 Trans am is F/60-15
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#12
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Yup that’s what I would run. 245/60/15 bf’s.
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#13
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Appreciate all the feedback and photos!
Sent from my iPhone using Tapatalk
__________________
Three times the sound peaks, falls back, peaks again. A throttling back to cruising speed, a dwindling grumble of thunder and...gone. The frogs take up where they left off. |
#14
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Quote:
Here's some pics:
__________________
"Those poor souls have made the fatal mistake of surrounding us. Now we can fire in any direction" 1970 Trans Am RAIII 4 speed 1971 Trans Am 5.3 LM7 1977 Trans Am W72 Y82 1987 Grand National |
The Following User Says Thank You to 72projectbird For This Useful Post: | ||
#15
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Quote:
https://tiresize.com/tiresizes/225-70R15.htm |
The Following 2 Users Say Thank You to 78w72 For This Useful Post: | ||
#16
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Quote:
My only complaint is the perimeter sidewall scallops/ribbing (for lack of a better term) looks too heavily textured to me. I prefer the total smooth sidewall look like on the original Wide Ovals and Polyglas tires, even the original Goodyear Eagle ST's...but, still they are very good tires. Dennis Dennis |
The Following User Says Thank You to SD455DJ For This Useful Post: | ||
#17
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Agreed. They almost look like off road tires from the side...
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keith k 70 Trans Am RA III / T400 / Lucerne Blue / Bright Blue 70 Trans Am RA III / M20 / Lucerne Blue / Sandalwood 70 Formula RA III / M21 / Lucerne Blue / Bright Blue |
#18
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#19
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#20
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ok, never really heard of anyone sizing tires by measuring when on the car, the weight of the car obviously changes the height of any tires stated dimensions. a f60 would be 24.5" based on that.
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