S.E. WI Newb with 1975 Le Sabre 455 Convertible

The car has 225/70/15 on it now. If I change tires I would like to use 235/75/15. Do they fit without rubbing?

 

I had them on my 74 Electra with no rubbing issues and i'm pretty certain they were optional from the factory on the 75 Electra and especially the Estate wagon.
Your Lesabre is only a bit shorter than the other 2 cars so the wheel wells I believe are the same.
I think the 235's are maby 1/2" bigger in diameter if even that.

I always liked the look of the big Uniroyal Royal seal tires with the one big white wall and name etched into the white wall.

 

From the 1974 Buick brochure:



The 1974 Electra and Riviera came with J85-15 tyres, that's 225/75 in metric.
The EW came with L78-15 tyres, that's 235/75.



'74 LSabres came with H78-15 tyres: that's also 225/75 in metric, according to the chart above.

225/75 = 75% of 225 mm = tyre wall height = 168.5 mm
15 inch rim size = 381 mm

So the diameter of a 225/75/15 tyre is 168.5 mm + 168.5 mm + 381 mm = 718.5 mm
718.5 mm = 28.28 inches

235/75 = 75% of 235 mm = tyre wall height = 176.2 mm
15 inch rim = 381 mm

So the diameter of a 235/75/15 tyre is 176.2 mm + 176.2 mm + 381 mm = 733.4 mm
733.4 mm = 28.87 inches

 

Yup, I got the same thing looking at the 75 Buick specs.
The Estate wagon was standard with LR78's or 235/75's
The wheel well area's has to be the same between all 3 models, only difference is wheelbase and length. I ran the 235's on my 74 Electra with no issues, rear fender squirt and all and even J78's or 225/75's on my 73 Riv.

Ok so I was a little close in size difference. .590 inches which is close to .250 inch taller on each side.
Other than the speedo being 2 or 3 mph off there isn't any reason to not go up a size. The OP though mentioned the tires aren't on his top to do list.

On another note, "Nailhead in a 67" I really wish you could sit near me and show me how to do the laptop/computer thing. I'm useless

 

Thanks guys. When the time comes, I'll go with the 235's. The fact that they were optional on some models solves the fitment issue in my mind.

I might make some time today and begin looking into the cold drivability issues. I'll stop for some carb cleaner. Going to spray all around and check for vac leaks. Pop the distributor cap and have a peek at it and the rotor, and so forth.

Today appears to be a beautiful day. Not going to take the car apart too much today. Much prefer to top down cruise it today. Save the digging into it further, for a gloomy or rainy day.

 

Oh yes, drive that car before the weather stops behaving!!
By the way does it have a posi as it was used for towing?

Edit: looking at the underneath pics and I see reversed white letter tires..

 

Nice LeSabre convertible!
My first car was like yours only in glacier blue with white top and interior.
350 car, ran good, the 455 isn’t much more powerful unfortunately

 

Thanks! I really am enjoying the car.

Have to disagree on the power comment. Yes it's the most anemic 455 they produced. It's still a big block. Torque is king on the street. Nothing makes torque like a big block.

When compared to the same vintage anemic 350. Well there is no comparison. Check the gap in torque curves. 85 ft lbs makes a huge difference in getting this barge rolling.