#21  
Old 08-16-2020, 09:23 AM
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Originally Posted by 69 Limelight View Post
I have a 69 GTO Hardtop. I run factory 15x7 Rally II's front and rear. I run BFG TA's front and rear. 225/70 x 15 on front that measure 27" inflated on car with 12,000 miles on them. 245/60 x 15 on rear that measure 26" inflated on car (same mileage but with more treadwear due to a few burnouts). At the front lower corner of rocker panel molding to ground measures 10" and at rear lower corner of rocker panel molding to ground measures 10 1/4" (no one in car and 3/4 tank of fuel) (do have a little stiffer spring on rear because do a lot of long distance trip driving and trunk is usually pretty full). On rear, closest point is tire to tailpipe (have 2 1/2" Pypes system mounted as close to frame rail was possible without rattling). Plenty of room sidewall to frame, and wheel well lip). On front closest point is at bottom of wheel well opening lip at rear of wheel well when turning. Could not use any larger diameter tire but, 69 front fender wheel well opening has a slight forward hook to it at bottom rear and I'm thinking a 70 is straight down. Some of these body guys would know if 69 and 70 use same front fenders. Oh, by the way, factory disc brakes which, if I understand correctly moves wheels outboard a fraction of an inch. So there you go.
Could you measure and see what the actual tread width is on your bfg 225 70 15?

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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'
  #22  
Old 08-16-2020, 09:30 AM
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Hey Scott,
I just installed 245/60/15 on all four wheels on my 70 gto conv. All fit and no problems with the fronts rubbing. The 245 on 15x7 rims starts to bulge outside the rim a little. The 255 on same set up would be noticeable.

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  #23  
Old 08-16-2020, 10:32 AM
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255 60 R15's were originally designed for use on 15x8 rims & their tread definitely roll over some on a 15x7. In the early to mid 80's I bought @ a good discount, & mounted quite a few Goodyear 255 60 R15's; Wingfoots & Eagle NCT's as well as a few Eagle GT's & BFG Comp T/A's.

The 255 60R15 Wingfoot & NCT had the exact same construction, same section width, same tread design & tread width, & when mounted on a 15x8 wheel, the same overall diameter. The same numerical size (255 60R15) Eagle GT had a near inch wider section width, slightly wider tread width, & when mounted on same wheels, were nearly a 1/2" taller. I preferred the NCT's on my own T/A as they were stickier. Also had numerous friends that I'd pickup 255 60R15 Eagle GT's for & few gave me their 1/4 tread Eagle GT's on the next go around.

Ever since that time, never thought it wise to refer to a tire height for any noted size, without actually having that particular product line of tire mounted on the width rim I was intending to use.

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  #24  
Old 08-16-2020, 11:29 AM
69 Limelight 69 Limelight is offline
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Default 70 GTO Tire/Rim Question

I measure 7 3/8"-7 1/2" actual tread width. Hard to get accurate measurement because outer edges are somewhat rounded and tread face not perfectly flat, especially since I have 12,000 plus miles on mine. Also, after your comment about diameter, remeasured my diameter and you are right. 245/60x15's measure closer to 26.5 and 225/70x15's closer to 27.4. Once again holding tape measure across diameter and using line of sight because largest diameter is in middle of tire due to tread is not perfectly flat. Would be more accurate measuring circumference and dividing by 3.14. Once again my rears also have 12,000 plus miles and several burnouts so diameter is going to be less than advertised but by no means is the tread depth close to replacement.

  #25  
Old 08-16-2020, 12:57 PM
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Thanks for the responses. I measured my tire diameters by taking 2 framing squares and holding them in a |__| shape,,kinda like big calipers. Sliding them evenly side to side in the middle of the rim until they touched the tire. Then measured in between.

OPH,,,yeah Im seeing now the advertised measurements arent real accurate from the tire companies. Thats why I finally just ordered a 15x7 and a bfg 245 60 15 to test. Like I said I think I prefer the looks from the outside the 15x7 over the 15x8,, the 8's look deep but it might be the way to go.

Limelight,,,thats not a bad actual width,,good to know.

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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'

Last edited by scott70; 08-16-2020 at 01:04 PM.
  #26  
Old 08-21-2020, 09:56 AM
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So I got a 15x7 with 4" b.s by vintiques rim and a 245 60 15 tire. Inflated they're 26 3/8" tall. A full 8" tread width. I think they look good. I see what some people say..this particular company the charcoal grey looks bronzy in the sun. Little shorter than I like but ok. Now the question is do I go 15x8 in the back with maybe a custom 4 .75" bs so the front dish looks very close to the front 15x7. Then put on a 255 60 15 .Or go all 4 the 15x7 with 245 60 15 ? Benefits there are i can rotate the tires.
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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'
  #27  
Old 08-21-2020, 10:08 PM
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So I tried the tire,wheel combo on the front. Definitely looks like it fills the front wheel well and wouldn't want any more tire up front. The oem 14x7 had 4 3/8" backset and these have 4" so they are set out a little further. I'm thinking about using that combo up front and maybe a 15x8 with a custom backset in the rear with a 255. Trying to keep the front reveal on all 4 rims close so the rears dont look like they are deep dish compared to the front. The front rim seems to have 3" of front "dish". If I go something like 15x8 with a 4 3/4" backset that will leave 3 1/4" "dish". If i went 5" backset the front and rear rims would have the same dish and look the same from the outside. With the 4" backset tire on the back it looks like there's about 2" of clearance between tire and frame/ inner wheel house. The reason im really trying to get this right the first time is because I've always thought the wheel/ tire combo can make or break the looks of one of these cars..So a 5" backset would leave about an inch between wheel well and tire. Is that enough clearance in the rear?
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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'

Last edited by scott70; 08-21-2020 at 10:24 PM.
  #28  
Old 08-22-2020, 10:38 AM
69 Limelight 69 Limelight is offline
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Default 70 GTO Tire/Rim Question

Scott, like I said in post #19 the closest point on my 69 GTO, at the rear, is tire to tailpipe. In your pictures it doesn't look to me that you have tailpipes on car yet and you haven't said what diameter you're using/going to use. I have 2 1/2" and have a "loose" index finger between tire edge (at tread face corner) and tailpipe and tailpipe to frame clearance is just enough that there's not rattle contact when I shake tailpipe. This is with factory 15" Rally II's with 245/60x15 BFG Radial TA's. Would hate to see you go to expense of custom backspace/width wheels and then won't work. No tailpipes, tailpipes not in factory location or 2'' tailpipes your probably good to go. Just FYI.

  #29  
Old 08-22-2020, 02:26 PM
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You're right...we put new mufflers on and haven't put the tailpipes back on yet. They're 2.5" dr.gas x from back in the day. I should throw one back on and check clearance. Thanks

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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'
  #30  
Old 08-23-2020, 04:08 PM
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Got about 2.5" between tire and tailpipe and about 2" from tire to inner wheel house with the 4" backset.
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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'
  #31  
Old 08-23-2020, 06:12 PM
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I think the 245's fill the back just enough so it doesn't look odd. I guess I'm going with this setup on all 4's. Yeah sometimes its hard to make a decision...lol. It'll probably settle about another inch when the rear bumper, glass,hood and things get put back on.
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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'
  #32  
Old 08-24-2020, 02:56 PM
69gtocv 69gtocv is offline
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[QUOTE=scott70;6171935]I think the 245's fill the back just enough so it doesn't look odd. I guess I'm going with this setup on all 4's. Yeah sometimes its hard to make a decision...lol. It'll probably settle about another inch when the rear bumper, glass,hood and things get put back on.[/QUOTE

And by going to 255's over the 245's, you would gain a whopping .4"! Hardly going to be noticeable. If you think you're going to put enough miles on the car that you'd want to rotate the tires, then I agree, keep them all the same size. LOVE the color by the way!

  #33  
Old 08-24-2020, 07:44 PM
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After staring at the rear for awhile,,,i finally came to the conclusion that I thought the rear would look a little better with the slightly bigger tire,,,,yeah its not by much. Got a special order today in on 15x8 with a 4 3/4" backset in at Vintiques and ordered a pair of 255's for the rear. So the fronts are 15x7 with 4" backset and 245 60 15. The rear rims will only have a 1/4" more "dish" than the fronts so not real noticeable at a quick glance. Sometimes I'm not good at making these "important " decisions...lol. Hopefully I'll be happy with them.
Thanks,,,original color of mint turquoise..Car will go back in the shop around October to be finished.

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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'

Last edited by scott70; 08-24-2020 at 07:50 PM.
  #34  
Old 08-25-2020, 07:22 AM
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Scott, I think you made the best decision going to the 255's on the rear with more back-space on the 15x8 rims to look more factory.

Love the color too!

Dennis

  #35  
Old 08-25-2020, 11:14 AM
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Scott,
I know you have received a lot of information so far. Here is some more. The pics of my ’70 are with Wheel Vintiques 15X7 both front and rear. I’m running 245/60/15 up front and 255/60/15 on the rear. I like the slight crown on the front side wall and the more noticeable crown on the rear.

I noted your comment early on that the 245/60 looked short up front. I have coil overs all the way around so I have the front setup for a slight rake. I really like that look.

Jim
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  #36  
Old 08-25-2020, 01:39 PM
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Here are pics of my setup-
Rear- 15x8, 4.75" backspace, 275/60/15
Front- 15x7, 4.5" backspace (I think, this is a stock mid 70's rim), 245/60/15
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  #37  
Old 08-25-2020, 03:07 PM
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Quote:
Originally Posted by napster View Post
Scott,
I know you have received a lot of information so far. Here is some more. The pics of my ’70 are with Wheel Vintiques 15X7 both front and rear. I’m running 245/60/15 up front and 255/60/15 on the rear. I like the slight crown on the front side wall and the more noticeable crown on the rear.

I noted your comment early on that the 245/60 looked short up front. I have coil overs all the way around so I have the front setup for a slight rake. I really like that look.

Jim
Your car looks good! I debated on all 15x7 but from reading the internet the majority thought the 255 should be on a 8" but your car looks good. I think my choice will work out good,,,thanks for the pics!

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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'
  #38  
Old 08-25-2020, 03:11 PM
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Quote:
Originally Posted by MrWrestlingII View Post
Here are pics of my setup-
Rear- 15x8, 4.75" backspace, 275/60/15
Front- 15x7, 4.5" backspace (I think, this is a stock mid 70's rim), 245/60/15
Your car looks great,,,i do like the black wall also,,I see why people do it. The pic with the stripe,,,did you lower the front of your car from the other pics? The factory red,white,black stripe is going back on my car after its wet sanded.

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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'
  #39  
Old 08-25-2020, 07:36 PM
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Quote:
Originally Posted by scott70 View Post
Your car looks great,,,i do like the black wall also,,I see why people do it. The pic with the stripe,,,did you lower the front of your car from the other pics? The factory red,white,black stripe is going back on my car after its wet sanded.
Yes the car is lowered in the recent pic with the stripe. I’ve been messing around with the ride height for a few years. I wanted the 275/60/15s to sit further in the wheel well and after trying a number of different Moog springs I had Coil Spring Specialties make me a set last winter. On the front I have old PST AC springs that now have 1.5 coils cut. I’d like the front to be just a bit higher than it is now.

I plan to put the AC back in the car, which I removed a few years back, and will try to get the front up just a bit during that project.

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  #40  
Old 08-26-2020, 06:15 PM
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Received the other 245 60 15 today,,,first one was made 26th week of 2020...this one is 17th week of 2019.

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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86'
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