Just purchased a sweet 1976 Cutlass Supreme. Had a76 Salon back in the day. Purchased new. I want to mount BFGoodrich Radial TA's. My salon had 4 H70-15's mounted now would be 235/70R-15. Anybody go any wider with stock SS III -5X7 rims?

 

H70 was a pretty tall tire @ 28.1 inches. Your right the closest to that is the P235-70-15. You can get away with a P275-60-15 on a 7 in wheel in the back and a shorter 60 series in the front.

Here's a good calculator:
http://www.discounttire.com/dtcs/infoTireMath.do

 

Thanks. I guess I'm what you call old school. I'm not a fan of the larger than 15 inch tires on the older cars but just love to have the widest tires possible keeping all 4 the same size.

 

You might see what 4 P255-60 or P235-60's look like on there. I think 4 P275-60's would make it look like truck.

 

Thanks for your advise. I will keep all of your suggestions in mind.

 

245 60 15s on all four corners will work well on your rims & look good on your car. You did not mention what rear gears you have but likely 2.73s. A tall 275 60 out back will kill off the line acceleration.

 

235/70r15 will fit with no problems,maybe a little tall as others said with most likely 2.56-1 gearing i suspect.

 

As Dave mentioned 245 60 15 is the biggest size that will fit all the way around without interference on the 15X7 wheels, provided your suspension or springs aren't worn out.