Tire size.

Discussion in 'The Bench' started by Ray carlson jr, Jul 1, 2020.

  1. Ray carlson jr

    Ray carlson jr Well-Known Member

    Hey guys looking to see thoughts on rim n tire sizes. 76 regal BBB. T350. 3:42gears. Wondering what width/height tire to go with. And how wide I can go in back with the stock 7.5”rims. Or if it’d be better to get different rims altogether. Any input appreciated. Thanks
     
  2. rkammer

    rkammer '71 GS455 Arctic White

    If your rims are the 15 inch Buick rallye wheels, they are 7 inch, not 7.5. If the 76 Regal is anything like the 71-72 Skylarks, the standard size for the wide oval tires was about 26.5 inches tall and was G60 x 15. And, the modern radial equivalent closest to that is the 245/60 x 15. You should be able to run that size on all 4 corners. If you want to go bigger on the back, perhaps 255/60 x 15 or even 275/60 x 15. Someone with a 73-76 Regal can confirm if these sizes will work on those years.
     
  3. Ray carlson jr

    Ray carlson jr Well-Known Member

    Okay thank you appreciate the reply
     
  4. 73 Stage-1

    73 Stage-1 Dave

    I have 275/60-15 Drag Radials on the back of my '73 on 15x8 Rallye wheels. It's a bit tight, but no rubs anywhere.
     
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    The available 15 X 8" Buick reproduction wheels have a 4 1/2" back space (0 offset). Whenever you look to use the widest tire possible, it always pays to take some measurements on both sides of the car. It isn't uncommon for the body to sit unevenly on the frame, resulting in more room on one side, and less on the other. Wish I had done that. I have the P275/60R-15's on 8" wheels, and it is very tight on my driver's side. I could easily use another 1/2" of back space (5") on that side.
     
  6. 73 Stage-1

    73 Stage-1 Dave

    Is that, or, was that an option? I have 15x7 and 15x8 repros, and while the back is perfect, would love less backspacing on the fronts. They sit tucked in too far for my liking...
     
  7. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    The 15 X 7's have 4" BS, the 15 X 8's have 4 1/2" BS. That is standard. You pay extra for special order BS.
     
  8. 73 Stage-1

    73 Stage-1 Dave

    Gotcha - who makes them special order? Hit google and fell down a rabbit whole of wheels... :oops:
     
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Call Summit or Jegs and special order them. They sell Wheel Vintiques and are full line suppliers. Not sure what the turn around time is.
     
  10. 73 Stage-1

    73 Stage-1 Dave

    I've been to the Wheel Vintiques site and didn't see the option. Excellent info - thank you.
     
  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

  12. 73 Stage-1

    73 Stage-1 Dave

  13. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    You're welcome. Let us know how you make out. I'll need to do this in the future.
     
  14. No Lift

    No Lift Platinum Level Contributor

    Dave, if you go that way, when you figure out how much BS you want on the Buick Rallys order them through Summit Racing. I was ready to order (4)8" w/5" BS for my '69 directly through WV. The lady told me it would be $25 each for the customization but $50 each to ship them! She said if you go through through Summit shipping is FREE. You need to tell Summit the wheels you want but with custom BS. They knew exactly what to do. Possibly, why not run some 1/4" spacers up front to space the 7" wheels out? No harm, no foul there and some big buck savings.

    As far as the '76 Regal goes you have to remember that they came with optional 215 75 15 tires which are 27.5" tall. Initially I ran 255 60 15's(27") on the factory 15 x 7's with 4 3/8" BS all the way around with no problem on my '76 Century. IMO the 255 is about as big as you want to go for a 7" wheel. 275 60 15's have been fitted onto 7" wheels but they really start to look too "bulgy". They will easily fit inside the rear but I would really recommend an 8" wheel for the 275's. 4.5" BS will work fine. 295 55 15 M/T Drag Radials(28" tall) fit nicely underneath the rear on 10" wheels with 5.5" BS which gives you effectively the same offset as the 8" with 4.5" BS. I've had that tire size on custom Buick Rallys and aftermarket lightweights. Currently for normal use I run Thrashstar 17 x 8 also with 4.5" BS and Nitto 255 50 17 tires. That size is all but identical in size to the 255 60 15's except for wheel diameter. This thread is when I initially installed them in anticipation of taking the car to the Texas Mile:

    http://www.v8buick.com/index.php?th...eels-something-different.231180/#post-1877026

    The 295 55 15's cleared the inside nicely but always looking for some extra rubber for racing I tried 325 50 15 M/T DR's on the same 15 x 10 w/5.5" BS and they got too close on the driver side(1/4") and wayyy too close on the passenger side(1/8") toward the front of the car. If both were at least 1/4" I may have kept them because the inside of the frame is very smooth where they were closest. I really didn't want to run spacers at the rear for racing. As Larry has stated you have to measure both sides because of things shifting around.

    As far as regular street tires go some 295 50 15's on 15 x 10's would work well although they are just under 27" tall. If I were to pair up with those I'd run 245 60 15's on 7's up front to keep the big and little look without going too short. You have to remember those wheel wells will swallow up tires, especially short ones.
     

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