285/40/18??

[vette427sbc]

I think I may be getting a new set of wheels this spring/summer and I'm trying to get everything figured out. I would really like to run a 285/40/18 in the back. the 285 is just about the same height as my 255/50/17's and they fit the wheel well perfectly. So my question is for those of you who run 275's on stock trailing arms (e-brake relocated, no swaybar. This is possible right?)...... can you spare 5mm of clearance to fit a 285?
Also...
The rear wheels I'm looking at are 18X9.5. If I have a 17X8 now with a 4" backspace and do not want to move the wheel's position, I would get the 18X9.5 with a 5.5" backspace right?

Heres a little photoshop I did of the wheels. Budnik Grid5's with the deep dish:

 

[lvrpool32]

I had 285/40/18's on 18 x 10's with 5.5" backspace, the tire would just touch the inboard side of the wheel well ,drivers side with a full tank of gas.

Nick

 

[mrvette]

It is my opinion you can do it without sway bar.....but you going to be SO close, I not really sure....you really shaving production variations there taking another .2? inch off that already tight clearance on MY '72 here, is really cutting it close....and IMO....too close....

course I have a sway bar in there with maybe 1/4 inch clearance on my 275/50/17 rubber....I going to play with some lowering on my car a tad here soon, need to get other stuff done first....

I scared of the fenders too....

:crutches:

 

[vette427sbc]

Gene, you saying that you DO run the swaybar with 275's?
I took the rear swaybar out a while ago.. so i dont have to worry about clearing that. do you have a good amount of clearance everywhere else though? Frame rails, TA, etc..

 

[mrvette]

Gene, you saying that you DO run the swaybar with 275's?
I took the rear swaybar out a while ago.. so i dont have to worry about clearing that. do you have a good amount of clearance everywhere else though? Frame rails, TA, etc..

YES< both stock and VBP ~3/4 rear sway bars clear MY 275 rubber but I have 2.5 inch wheel adapters with now '89 vette wheels 17x9.5 .....I have a stock sway bar back there now...and the clearance is tight....about 1/4 inch or so...

the issue is NOT frame, it's a inch or more in the rear/top....the stock T/arm is about 3/8 inch or so...non offset, but obviously the ebrake bracket was moved....

IF I had a set of offset arms, and NO swaybar, I could fit a great amount of tire back there,......

now also to consider, my car WAS a old show car from decades ago...and as such had silly flares on it...reduced to late shark proportions now....

as it is 10" of rubber is plenty anyway....

:ghost:

 

[TimAT]

Ol' Red has 285/40x17's on the rear with 17x9 wheels and 4" backspacing. NO mods to the T/A's, e-brake cable or anything else. Still running the stock sway bar too. You could throw a cat thru there and not hit anything.