Will these fit

Discussion in 'Pro-Touring' started by Swagon, Mar 13, 2018.

  1. Swagon

    Swagon Well-Known Member

    I currently have a 15x7(I assume 4"-4.5" back spacing) with a 235/60 tire and a 15x8(3.75" BS) with a 295/55 tire. would a 18x8(4.5" BS) and a 245/45 tire and 18x9.5(5.5"BS) 295/40 fit?
     
  2. 87GN_70GS

    87GN_70GS Well-Known Member

    Yes, I would think so
     
  3. redsixty9

    redsixty9 Platinum Level Contributor

    I think they will fit with the extra back spacing and some trimming. I currently have a set of 18"x 8" with 4.5 backspace on front and a 245/40/18" they fit fine. The taller tire may or may not be a issue. On back I have a 18" x 9.5 with 5.25 back spacing with a 275/40/18". The rear is too close to the wheel well opening for my liking. I could trim the wheel well or roll them and make them work. You can only go so far toward the qtr panel because the outer well will hit the tire. I plan on putting at least a 295 on back. I really think a 305 or possibly a 315 will fit on a 10" or 11" wheel with the right back spacing. I definitely have to have wheels made to make it right. The only thing stopping me is spending the $3500 for the wheels is making sure my measurements are good. I plan to do some fabricating to the rear wheel housings to give me maximum clearance before I strip and paint the car. I was surprised how much room I had between the tire and the frame with the 275.
     
  4. ilikebmx999

    ilikebmx999 Well-Known Member

    I was under the impression the 68/69 cars had smaller openings. I have very similar sized wheels/tires and they fit fine on my 70.
     
  5. redsixty9

    redsixty9 Platinum Level Contributor

    They do have smaller openings and sit lower on the tire. When I have the 15 inch tires on I have to unbolt the rear coil over shocks to stuff the bigger sidewall in. I have to shim the wheel out with a 1/4" spacer to clear the rear disc caliper also. With the 18" wheels and tires I don't need to drop the shocks due to the lower profile of the tire and the disc brake caliper clears the rim without the shims. I have a old set of 15" Cragar street stars and they may fit without the spacer on a GM caliper but not with the baer brakes I have. I used the biggest rotor I could fit and use a 15" wheel. This way I could run a slick with bigger sidewall for the drag strip and a larger wheel for the streets to take advantage of the handling package the car has and the look I want. I actually bought the 18" wheel package off craigslist because it was a good deal and thought I might be able to use them. They are for sale and like brand new. I have $1050.00 invested them and will post them soon US mags U111 on Cooper tires.
     
  6. 1972Mach1

    1972Mach1 Just some M.M.O.G. guy.....

    As far as the tires themselves go, you're actually putting about 1/2" shorter on the rear, so if you can get your backspacing figured out, you'll be fine. Here's a tire size comparison calculator I like to use: https://tiresize.com/calculator/
     

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