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Old 05-25-2012, 08:54:29 PM   #1
nicks78camaro
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Backspacing/offset?

What's the optimum backspacing and offset to run for a 1978 Camaro with 15x7" up front? I'm looking at getting the Centerline Competition Series Rev wheels




Also with a 275/60/15 tire, would you run a 15x8" or 15x10" wheel? Would a wider tire fit in the rear of a second gen without modifications?

Also, does anyone have these wheels on a second gen (black car?)

Thanks guys!
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1978 Camaro LT
-Factory triple black
-Built 355, aluminum heads, Lunati VooDoo cam
-Built TH350
-4.10 gears

1980 Camaro
-Black
-Black interior w/white seats
-305, TH350, 3.42 posi
-vintage 350SS cam
-Weiand intake, Edelbrock 600 carb
-ceramic coated long tubes, mostly stock
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Old 05-25-2012, 10:45:13 PM   #2
The Champ
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Factory BS on the 15x7" steel wheels was 4.25".

Many members have 275/60/15's on their Camaros.
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Old 05-25-2012, 11:44:43 PM   #3
nicks78camaro
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Are they zero offset? also would the 275/60/15 work better on an 8" rim?

Also, what is the widest tire that can fit on the rear with 15" diameter rim with no modifications?
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1978 Camaro LT
-Factory triple black
-Built 355, aluminum heads, Lunati VooDoo cam
-Built TH350
-4.10 gears

1980 Camaro
-Black
-Black interior w/white seats
-305, TH350, 3.42 posi
-vintage 350SS cam
-Weiand intake, Edelbrock 600 carb
-ceramic coated long tubes, mostly stock
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Old 05-26-2012, 02:44:11 AM   #4
HyPer
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15x7 with 4.25 BS would be a +18mm offset. Most 275/60s are recommended for 7.5-8.5" rims. I've got a set on a roller at the moment, rims measure out at 7.5", they definitely give that old school "WIDE-60" look.
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Old 05-27-2012, 11:26:36 PM   #5
nicks78camaro
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Ok so the Centerlines come in 3.5, 4, and 4.5" backspacing.

I was gonna get 15x7" front, and 15x8" rear.

I know 4.5" backspacing for the rear, but what about the front? 4"?
__________________
1978 Camaro LT
-Factory triple black
-Built 355, aluminum heads, Lunati VooDoo cam
-Built TH350
-4.10 gears

1980 Camaro
-Black
-Black interior w/white seats
-305, TH350, 3.42 posi
-vintage 350SS cam
-Weiand intake, Edelbrock 600 carb
-ceramic coated long tubes, mostly stock
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Old 05-28-2012, 10:34:35 AM   #6
rchydzik
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If you have a zero offset wheel, backspace will slightly larger than you expect due to the tire mounting lip (1/2 inch). For example, a 15x7 wheel with zero offset has a backspace of 4 inches.

7/2 = 3.5 inches
3.5 + 0.5 (tire mounting lip) = 4 inches backspacing

If the factory backspace is 4.25 inches on a 15x7 wheel, it has an offset of 0.25 inches (6mm).

Having said all that, I ran 15x7 (no offset, 4 in backspace) all the way around with 235/60R15 tires with no problems for years. I also ran 245/60R15 with no problems, but that size and rubbing can vary by car.
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Old 05-28-2012, 12:17:32 PM   #7
Tokyo Torquer3
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After my recent experience with the Cen*%line wheels. i would not go near that brand again. After 6 months back and forth with wheels that would not balance because of very bad run out, I kept sending them back and the replacements they sent were just as bad. I heard this is a well known problem with the brand. Moreover, while the faces where polished nice, the backsides were totally hideous with weld spatter and pits in the finish everywhere. I ordered through Summit and the pics I sent them were bad enough that they totally refunded my money and added some gift certificates to compensate for my exerience. I went with another brand and all is well now.
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Old 05-28-2012, 02:35:18 PM   #8
nicks78camaro
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^oh wow that's news to me, thank you for the advice
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1978 Camaro LT
-Factory triple black
-Built 355, aluminum heads, Lunati VooDoo cam
-Built TH350
-4.10 gears

1980 Camaro
-Black
-Black interior w/white seats
-305, TH350, 3.42 posi
-vintage 350SS cam
-Weiand intake, Edelbrock 600 carb
-ceramic coated long tubes, mostly stock
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Old 05-29-2012, 04:39:28 PM   #9
nicks78camaro
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Posts: 832
So are the Weld Magnums better than the Centerlines quality-wise?
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1978 Camaro LT
-Factory triple black
-Built 355, aluminum heads, Lunati VooDoo cam
-Built TH350
-4.10 gears

1980 Camaro
-Black
-Black interior w/white seats
-305, TH350, 3.42 posi
-vintage 350SS cam
-Weiand intake, Edelbrock 600 carb
-ceramic coated long tubes, mostly stock
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Old 05-29-2012, 05:01:19 PM   #10
Tokyo Torquer3
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Location: NJ
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Weld makes great wheels, they are not in the same league.
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1973 RS Z28: 401ci Dart Little M, Littlefield 8-71 supercharger @14lbs boost, Callies Magnum crankshaft, Lunati Pro-Mod rods, JE pistons, 7.8:1 compression, AFR 227 Comp heads, T&D 1.6 shaft rockers. Reed solid FT cam (240/250@.050, .523/.542 lift, 112 LSA), QFT 750 carbs, Lemons headers, Mezier mechanical water pump, Tremec TKO-500 5-speed, Moser 12 bolt, 33 spline axles & 3.42 gears.
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Old 05-31-2012, 12:55:47 AM   #11
AJ_72
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I have the sizes you're looking at on my car. Weld Draglites. 15x8.5 in the rear with 275/60/15", 15x6 in the front with 215/70/15.

The rear backspace is 4.5". The front is 4".

Sorry it's not black, nor the style of wheel you want, but the sizes are close.



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Old 09-13-2012, 02:29:15 PM   #12
n00b
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What would the correct backspacing and offset be for 17" x "8 wheels?

1978 Camaro, planning on running 235/50ZR17.

Thanks!
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Old 09-14-2012, 08:30:06 PM   #13
Orange71
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275/60's on an 8" rim with 4.5" BS will fit fine. Up front 235/60's on a 7" rim with 4" BS will work. At least on mine they did!
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