Enter your username:
Do you want to login or register?
  • Forgot your password?

    Login / Register



    Results 1 to 8 of 8
    1. #1
      Join Date
      Dec 2020
      Location
      San Clemente
      Posts
      2

      Looking for help on wheel/tire size + backspacing for a 70 Chevelle SS

      Title says it all. I've got a 70 SS that still has the original 14" rally rims & the original suspension.



      I'm not looking to put the biggest wheel/tire combo but I'd like to know if I can fit Rocket Attacks 18x8 in the front & 18x9 in the rear. After reading a lot of threads on this site & others, I believe those rims will fit but I'd love to see if there's anyone on here whose run those sizes & what backspacing to use. I'm not sure on the tire size, but again, something relatively big but not the biggest as I'm not autocrossing & am looking to avoid any rubbing issues. Thanks in advance.


    2. #2
      Join Date
      May 2010
      Location
      kitchener,Ontario,Canada
      Posts
      2,169
      Country Flag: Canada
      those sizes you will be fine , I cant give you backspacing but can tell you that you can easily fit 275s on all 4 corners and wont even come close to rubbing ( with right backspacing )
      Spinnin'my tires in life's fast lane

      Ryan Austin
      On twitter @raustinss
      On Instagram austinss70

    3. #3
      Join Date
      Dec 2020
      Location
      San Clemente
      Posts
      2
      Quote Originally Posted by raustinss View Post
      those sizes you will be fine , I cant give you backspacing but can tell you that you can easily fit 275s on all 4 corners and wont even come close to rubbing ( with right backspacing )
      So does that mean I could run an 18x10 in the rear? My backspacing options with that rim (Rocket Attack) are 4, 4.5,5 & 5.5" front & rear. I'm thinking 4.5" bs on the front 18x9 & 5" bs on the rear as I'd like to have room for a bigger disc brake set down the road.

    4. #4
      Join Date
      May 2010
      Location
      kitchener,Ontario,Canada
      Posts
      2,169
      Country Flag: Canada
      I'd suggest , doing a search on the largest tires you can fit . There is a chart i have seen and it had the backspacing listed . This chart had a bunch of different sizes and backspacing set ups . hell very little work and you can have 315s on the front lol
      just googled something for you 18x9 (5.5" b.s) with 275/35/18 for the front and 18x10 ( 5.75" b.s ) with 305/35 drag radials is what another member was running with no problems .
      so maybe a 18x10 with 5.5 bs would be just fine
      Spinnin'my tires in life's fast lane

      Ryan Austin
      On twitter @raustinss
      On Instagram austinss70

    5. #5
      Join Date
      Dec 2008
      Location
      Detroit
      Posts
      2,461
      Country Flag: United States
      Quote Originally Posted by 70-SS-502 View Post
      So does that mean I could run an 18x10 in the rear? My backspacing options with that rim (Rocket Attack) are 4, 4.5,5 & 5.5" front & rear. I'm thinking 4.5" bs on the front 18x9 & 5" bs on the rear as I'd like to have room for a bigger disc brake set down the road.
      Yes you can easily run a 10" wide rear on a 70 Chevelle. Common backspacing for that would be 5.75
      Big dreams, small pockets....

      Chris--
      '72 Cutlass S LS2/T56 Magnum
      Bowler Performance, Rushforth Wheels, SC&C, ATS, Street Rod Designs, Speedhut, KORE3, Ridetech

      Project Motor City Madness

    6. #6
      Join Date
      Oct 2004
      Posts
      2,438
      Country Flag: United States
      From others on here it seems the ideal backspacing is +6mm. That's 5.5" for a 9" wheel and 5.75" for a 10" wheel.

      Couple options if you want to stick with the Rockets:
      1. You could run 18x9s w/5.5"bs with 275/35s all around. It's a little shorter than the stock tires and since you'd be at minimum rim width for that tire, it'll feel less responsive in cornering than same tire width the on a 10" wide.
      2. Or, you could use the 18x10s w/5.5" bs and run 265/40s on all four corners. This is closer to the stock tire height, and should still work even with the offset being .25" too shallow.
      Red Forman: "The Mustang's front end is problematic; get yourself a Firebird."

    7. #7
      Join Date
      Dec 2012
      Posts
      15
      Country Flag: United States
      Best to measure.

      Often an 18x10 with 5.75" backspace will fit the rear. But get into 285/40/18 tires and disc brakes, and you may have a problem. If you don't have discs now, don't assume you won't in the future. 18x10 with 6" backspace may be better, but check exhaust, etc. behind the tire. Every car is different, assume nothing based on what worked for someone else.

    8. #8
      Join Date
      May 2010
      Location
      kitchener,Ontario,Canada
      Posts
      2,169
      Country Flag: Canada
      Quote Originally Posted by 72mojave View Post
      Best to measure.

      Often an 18x10 with 5.75" backspace will fit the rear. But get into 285/40/18 tires and disc brakes, and you may have a problem. If you don't have discs now, don't assume you won't in the future. 18x10 with 6" backspace may be better, but check exhaust, etc. behind the tire. Every car is different, assume nothing based on what worked for someone else.
      why are you suggesting more offset ? , also the exhaust on that car doesnt enter the wheel well
      Spinnin'my tires in life's fast lane

      Ryan Austin
      On twitter @raustinss
      On Instagram austinss70