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Need help w/ tires

1974 Views 13 Replies 7 Participants Last post by  Jpack
I am currently buting new wheels and tires. I am looking at Zr1 17 by 9.5 wheels w/ 275 40 17 tires. I need to know if i use these tires will they stick out of my fenderwells and will the clear the inside of the wheelwells in the front. Does anyone have any suggestions on a good tire size for the front or rear tires that will fit without alot of modifications
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4th gen or 3rd gen?
its a 3rd gen
Depends on the backspacing of the wheels.
it is a 56mm offset
You should be able to fit 275/40/17 on the back and 255/40/17 on the front with no issues.
What about 275s all the way around on a 4th gen
You need spacers to run 4th Gen wheels on a 3rd Gen.

Edit: According to your profile you have an LT1 Formula. Thats a 4th Gen.

The SS/WS6 cars came factory with 275/40 17s on all 4 corners. They should fit fine all the way around.
I think you should put true ZR1 rims on the car with the 17X9.5 275 front and the 17X11 315 rear tires. Those look real mean on 4th gen f-bodies, and they tuck into the fenderwells very nicely, GM should have sent these cars out that way from the factory. The cost is not much more than 275's all around, trust me the look is worth it :thumbsup: . Check EBay, there are several vendors who can sell you a set for a decent price.
What backspacing or offset should i look for if i go with theses sizes
Enthusiast said:
What about 275s all the way around on a 4th gen
I run them on mine, was a direct change out. Need 56 mm offset though.

This size likes to grab the ridges in the road. FYI
I found a set of tires w/ 17 by 19.5
38 mm backspacing for the front and 17 by 11 +36mm backspacing for the rear with 275/40/17 up front and 315/35/17 in back will these work on my car
Camaro & Firebird Fitments

Bolt Pattern

5 x 4.75" or 5 x 120.65 mm

The numbers in the columns are as follows:


Front and Rear

7.0" ..... +35 to +40 mm .... 215, 225, 235
7.5" ..... +35 to +45 mm .... 215, 225, 235
8.0" ..... +38 to +55 mm .... 225, 235, 245
8.5" ..... +38 to +45 mm .... 235, 245, 255
9.0" ..... +38 to +56 mm .... 255, 265, 275
9.5" ..... +38 to +56 mm .... 255, 265, 275
10.0" ... +38 to +48 mm .... 265, 275


10.0" ... +38 to +54 mm .... 275, 285
10.5" ... +38 to +50 mm .... 285, 295
11.0" ... +45 to +56 mm .... 315

Z06 Corvette Replicas:

17"x9.5" +50 to +56 mm no problems. 275/40R17.

18"x9.5" +50 to +56 mm 275/35R18 or 285/35R18.

18"x10.5" +50 to +53 mm. Higher than 53 mm will require the BFH mod. 285/35R18s thru 315/30R18. Over 295 may require rolling the fenderlip and will need the BFH.

Y2k Corvette Replicas:

17"x8.5" +56 mm

17"x9.5" +50 to +56 mm

18"x9.5" +50 to +56 mm

17"x11" Wheels

ZR-1 Style for Camaro +50 mm (Known as Grand Sport offset)
ZR-1 Style fo Firebird +36 or +50 mm The wheel well on the "bird" is a little wider.

American Racing TT-2's +45 mm

With 17"x11"s there is always a possibility of needing the BFH and/or fender rolling mods with 315s. If lowered, an Adjustable Panhard Bar becomes a virtual necessity. Some have used the +38 offsets with an 11" wheel but it does stick outside the fender and is definitly not recommended on lowered vehicles. +50 and +56 are the two most common. +50 is the better fit (for the ZR-1 replica).

For road race only applications a 17"x11" at all four corners can be made to fit

Will check on third gen for ya.
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Here is a great link. Should answer any and all tire/wheel fitments.
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