I run 255/60 15's on rear and had a little rubbing but it stopped after adding new shocks,subframe connectors and rear springs. Ran Kyb shocks but they are junk, stepped up to Koni but they provided little difference and finally replaced with RS 9 position rear shocks and I am pleased with the results. Installing rear shocks is a breeze!

 

You don't even need to open the trunk - it can be all done from the whell well side. The top of the shock is mounted to a diamond shaped plate that is held in with two 5/16-18 bolts. (1/2" socket) Remove those two bolts and pull the shock out along with the mounting plate. A long extension with a wobbly is handy. Install the plate onto the new shock and reinstall to the car. Especially handy on a 68-69 convert for the pass side shock, the top of which requires removing the back seat for good access. Either way works fine, though.

 

I run 255/60/15 on 15x8 rims with 4.5 backspace. No rubbing on my 67.
When I changed my shocks, I chased the threads of the old shock stud with a die then used penetrating oil on the nut for easy removal.
New shocks are Koni classics, cant comment on them yet, the weather has kept the car indoors but, I can tell you the KYB gas adjusts that were in there rode like an empty dump truck.

 

You should not be rubbing at all with 235's or 255's on the rear. Even 275's with correctly back spaced rims will not rub. What size are your rims and what is the back spacing on them?

 

Matt is correct- 255's should not rub if backspace is correct.
Are you using 15X8 corvette rally wheels? They only have 4" backspace and you need 4.5".

 

Shocks are easy as the others have said but they typically won't help stop tires from rubbing... 235's should fit easy unless mounted on wheels with the wrong backspacing and if they rub then 255's on the same wheels will also rub. Too much back spacing will cause the inside of the tire to rub and too little backspacing can cause the outside of the tire to rub.

Back in the day a lot of guys ran with very little backspacing and jacked the back end of the car up to stop the rubbing. This allowed for deeper dish wheels, wider tires and a wider stance (foot print) in the back.

Where do your 235's rub?

 

I'm running 245/60's in the rear on 7x15 TTD's with 3.76 BS and have no rubbing with 4 in the car. I have Hotchkis springs, SFC's, poly bushings, and Bilstein shocks.

 

If you have 235's and they rub going to 255's (wider) won't eliminate the problem! Where do your 235's rub, inside against the inner fender or outside against the fender lip?

 

If you have 235's and they rub going to 255's (wider) won't eliminate the problem! Where do your 235's rub, inside against the inner fender or outside against the fender lip?

Thanks for the response. They only rub when i hit the gas really hard and it's in the rear. Sounds like they are hitting the top of the fender, not the side, but i would have to drive it to double check and my car is not riding at the moment. I believe it has to be inside the fender because when i go over bumps hard or hit that gas, that is when i'm feel and hear the rub. I want to add good shocks and i am looking at some Gabriel ultra shocks for it. The Gabriel shocks are low priced. Then i see the Edelbrock shocks and they are almost a bill each. Does it make much of a difference in these rear shocks ? I mean i hear you get what you pay for, but will this matter here in rear shocks ? Thanks

 

Can you find scrape and rub marks on the sidewalls of your tires or inside the fender well anywhere? Does your back end really squat (bottom out) when you get on it? Same when going over a speed bump?

Can you measure from the inner fender wall to the sidewall and from the fender lip to the sidewall?

As for shocks, good shocks cost more than ok shocks, if you are buying $100 each shocks get Koni Classic or Bilstein... I have a friend running the edelbrock shocks with the 4wd boots and he's happy with them. I haven't ridden in his car though to compare... Shocks are intended to control the ride and movement of the suspension not be the suspension, what do you know about the springs on your car? Shocks with the exception of air shocks do not or should not control the ride height...

 

might ask someone that has run spacers. a parts store guy told me about them but I have never ran them could held with backspacing. mark

 

Spacers (assuming wheel spacers) fix too much BS, he needs more BS.

 

I ran 245 x 60 x 15 at one time on std YH rally wheels. Only rub point was in front where the tire was rubbing the headlamp door plastic cover. Did a little rub on the opposite side in wheel well but no isses with rear.

I now run 245 x16 x 50 on 8" wheels with BFG Traction GForce. No issues except BFG quit making this tire.

I have Koni 3way all around like I started out wth 40 years ago. I tried KYB's several times, just too spongy.

I probably could get the 255 x 50 in rear but front would be an issue plus I would not be able to rotate front to back, just side to side.

 

Lex did you ever take measurements to make sure your rear end did not get moved to one side when you smacked that curb?

 

Where would i have to measure ? That might have happened. I did hit extremely hard, that is why my (steel) rim was destroyed in the rear. As an average joe, even if i looked under i might not notice. I will take it into a shop as soon as i get the shocks and rims put on with tires.

@ Calpantera - Yup, all that from one strong smash hit. Well add about two spins to it, lol ..

 

Well guys i checked the rear where i hear and feel the tire scraping and there are markings in the back inner fender passenger side. Here is a picture of the tire markings in the rear.

 

This would mean too much back spacing, no? I thought we were talking too little. If that's where the rub is and the wheel needs to be "pushed out", I would try a .25" spacer which may do the trick. I had a very minimal inner rub on my setup and the spacer did fix it.

 

This would mean too much back spacing, no? I thought we were talking too little. If that's where the rub is and the wheel needs to be "pushed out", I would try a .25" spacer which may do the trick. I had a very minimal inner rub on my setup and the spacer did fix it.

From my understanding my cragar prostar rims were 4.5 bs and now i have corvette rally rims which are 4 bs. Maybe now it won't rub ?

 

Ok fellas, i just finished putting back the old tires i had from the accident (235/60/15's), i'm must trying to get this car back on the road and off to shops for break service. After putting back the rims with these tires it looks like there is plenty of room for even taller tires, i don't see much space for wider. As i placed back the rims i noticed on the drivers side rear there is a broken bracket - is this a big deal ? I placed a picture below, it goes around those long steel suspension parts.

 

Here you go Lex..http://shop.stevescamaroparts.com/Leaf-spring-rebuild-clamp-kit-4-leaf-251270.htm
Their leaf spring clamps and need to be replaced.