My ‘75 corvette is stock, but I’m wanting to buy new wheels and tires. I’m wanting to go as wide as possible in the rear. I really need some advice. Please help!!! Thank you!!!

 

Good Question....awaiting answer as I, too, have a '75.

 

There are numerous threads about this on the forum, mostly separated by rim size so really it comes down to what you are looking for. Bear in mind that this is very largely personal preference so you will get answers that are all over the place based on what different people find appealing. My recommendation is to do your own homework.

If keeping to originality, then you will be looking at 15" wheels and tires. Going to a larger sized rim will allow you access to better tire compounds so your car will handle/ride better but it does change the aesthetic of the ride. Many are going 18" these days simply because finding rubber for <17" wheels is becoming more difficult. Personally, I went with 17" rims specifically because I like the wider sidewall look on these cars.

As far as tire width goes, I have done a TON of digging on this subject as I am just about to make a tire purchase and what I have uncovered is that for widest you can go without ANY trouble at all is 245's. Many report that 255's are just fine but there are a few that reported rubbing with them. These cars are all a little bit different so what works for one may not work for another. Fewer have reported going even wider than 255's without a problem but they are in the minority. If you are comfortable with removing the rear trailing arms and relocating the parking brake bracket on them (requires welding) then you can safely go to a 275 in the rear...again this is not first hand experience, just what I have gathered from researching this here on these forums.

Some things to consider:

The overall tire diameter to fit 'properly' in the wheel well is 27", both for appearances and also to prevent rubbing. I would strongly recommend sticking to a combination that gives you that same overall O.D.
The larger you go with rim diameter, obviously the smaller the tire sidewall will be. This gives great handling but also gives it a firmer ride and also has a much more modern look to it...this was the reason I went with 17's as I felt it gave me the best compromise of both looks and performance.

This is what I mean. Both examples below have an overall tire diameter of 27"

A 15" rim has a ~6" sidewall



An 18" rim has a ~4.5" sidewall. It may not seem like much but it does make a large difference in performance and appearance. There is far more rim visible and less tire, if that makes sense.


This is a great reference that I used to help find the right wheel/tire combination. Just go to the tab for the rim size you are considering and then look under the 27" heading. It will show you the options available to you.
https://tiresize.com/chart/

 

Excuse me but I had to but in as I have the same rim and red rimsaver combo but don't have raised white lettering, I just love the look, thanks, I'm getting out the white sharpie!!!!!


Your tires look cooler than mine and i want the chrome roll bars

 

those dont look like 18s on the Nissan, heres what 18s and 26.7 in tall tire looks like on a 79

 

I have 275/60/15 on the rear.

 

There is a sticky post for this very purpose.