'73 Z28. Widest Wheels. Right Suspension. No Cuts

Discussion in 'Suspension, Steering, Brake & Wheel Topics' started by drLocke97, Nov 6, 2017.

  1. NOT A TA

    NOT A TA Veteran Member

    Feb 12, 2009
    Delray Beach Florida
    For me it began when Hotchkis built the F-71 Camaro back around the turn of the century. The car showed up on the cover of Hot Rod wearing a 315/275 17" combo IIRC without wheel well mods. At the time I was building my 70 bird and also had a 71 Z-28 and a 74 Type LT so I started measuring and comparing the wheel wells. Then called the Hotchkis tech guys. Then measured again, and again, and again because you can't return custom wheels if you screw up.

    Early 2nd gen F body's before the retractable rear seat belts have the most room followed by the belt hump ones and then the mid/late models with the large rear window seem to have a little less. The Firebird's round wheel openings seem to allow a little more suspension travel or vehicle lowering before the fender lip becomes an issue compared to Camaros. Trying to drop the car really low and "tucking" the tire doesn't usually work out well with 315's.

    315's are about the width limit without modifying the wheel well other than the belt hump on early 2nd gen F cars. There's a bunch of factors that contribute to determining what will work on a particular application, including (but not necessarily limited to) vehicle weight, spring rates, shock choices and settings, anti roll bars, use of Watts link or Panhard, payloads, vehicle use, rim width, tire diameter, and tire shoulder. As noted above, the brand and model of tire comes into play because one companies 315 isn't the same as other's 315's.

    For many years I ran 275 40 17 on 9.5" front and 315 35 17's on 11" rear. Wheels were A.R.E. TT II's with Yokohama AO 48 tires with a Hotchkis/Bilstein suspension combination purchased before they offered TVS as a package. No payload (not even spare tire) and did not ever have any issues street driving. On road track I did get a very slight rub on the inside of the wheel well near the shock, only if I hit corner curbing too hard at full boogie on one corner at Road Atlanta and one corner at Sebring. A Watts or Panhard would prevent that rub but I've gone slightly narrower on my new wheels/tires.

    My new wheels are Rushforth Night Trains in 18 X 10 all around with Yokohama AO 50 285/295 30 tire combo. I've replaced all suspension to PTFB products, and brakes are Baer 14" so everything below the frame is different now and not tested yet.

    Here's my old 17" setup with the 275/315's, pics taken before disassembling the entire car for a bare metal rotisserie restoration with lots of upgrades.




    G72Zed, 71RSLS and Seventy1ProTour like this.
  2. Turbo70Camaro

    Turbo70Camaro Veteran Member Gold Member

    Jan 7, 2005
    so cal
  3. LoweRider

    LoweRider Member

    Jun 26, 2017
    TX, USA
    Back when I owned my 79 years ago, I ran 315/35/17 in the rear with no clearance issues. I did get a little rubbing though if i went through a small dip too fast or the rear wheels on uneven height road. Will be doing the same thing on my 81Z I'm working on

Share This Page