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Old Feb 24, 2015 | 03:52 PM
  #1  
Christophe2m6's Avatar
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From: France
Another tire size question!

Hi Guys!

The question is for a 1969 Supreme 350ci!
Tried to search the answer on the forum first, then in the manuals.

And I found that my car had 7.75-14 tires!

Would like to find the nowadays size, and found 2 sizes:
205/75-14
215/70-14

And my car has actually a mix of both sizes: 215/75-14!

So which size should be the "correct" one?

Thanks a lot!!
Old Feb 24, 2015 | 04:35 PM
  #2  
oldcutlass's Avatar
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Posts: 42,475
From: Poteau, Ok
The following are the dimensions of the tires:

7.75-14 7.65" section width, 27.02 diameter

205-70-14 8.07" section width, 25.30 diameter
215-70-14 8.46" section width, 25.85 diameter
215-75-14 8.46" section width, 26.70 diameter
225-70-14 8.86" section width, 26.40 diameter

Your still going to come up shorter than the stock size by going to a radial. If you go to a 235-75-14 then your into the light truck or expensive vintage tires.
Old Feb 24, 2015 | 04:53 PM
  #3  
rcorrigan5's Avatar
Randy C.
 
Joined: Feb 2009
Posts: 3,348
From: Albany, OR
The tire my '68 4-4-2 originally came with was also a 7.75-14 and I went with a 215/70R14. On original steel wheels, they work nicely. On original SSI rims, the front tires rub slightly against the front part of the frame when steering is hard over to the right or left. It all has to do with backspacing, of which the SSI wheel has a deeper backspacing than the steel wheel. I'm planning to put on 215/70R14s on my '69 4-4-2 as well. The '69 has the SSI wheel for disc brakes and the backspacing is about the same as it is for the steel wheel.


Randy C.
Old Feb 25, 2015 | 08:03 PM
  #4  
joe_padavano's Avatar
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From: Northern VA
Personally I'd go with the 225/70-14s. These will fill the wheelwell nicely. Redlines would look awesome.
Old Feb 25, 2015 | 09:31 PM
  #5  
chip-powell's Avatar
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I must be the odd one around here. I have 235/70R 15's on mine. I just felt like I was going to bottom out with the 14's.
Old Feb 26, 2015 | 07:17 AM
  #6  
oldsmobiledave's Avatar
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From: Delta BC Canada
tires

Originally Posted by chip-powell
I must be the odd one around here. I have 235/70R 15's on mine. I just felt like I was going to bottom out with the 14's.


235 70 15s are 28" tall. That is a very tall tire. What are your rear end gears? Your speedo must be way off (you are travelling way faster than you think you are).
Old Feb 26, 2015 | 11:15 AM
  #7  
chip-powell's Avatar
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From: Maryland
Originally Posted by oldsmobiledave
235 70 15s are 28" tall. That is a very tall tire. What are your rear end gears? Your speedo must be way off (you are travelling way faster than you think you are).


Actually, it's not that tall at all (It is very wide though on those 15x7 cragars). With these tires, the bottom of my cutlass is sitting just under 5 inches from the ground. My speedo is a little off though. I'm actually traveling 5 mph slower than what my speedometer is reading. Go figure.
Old Feb 26, 2015 | 07:34 PM
  #8  
joe_padavano's Avatar
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From: Northern VA
Originally Posted by chip-powell
I must be the odd one around here. I have 235/70R 15's on mine. I just felt like I was going to bottom out with the 14's.
The OP specifically asked about 14" tires. I have 15s on all my cars (except the 62).
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