Wheels and Tires Need help with wheels or tires? Got fitment issues? Have questions about tire performance and handling? Ask all of those questions here!

Fitting C4 ZR1s on a 4th gen rear axle

Thread Tools
 
Search this Thread
 
Old 08-04-2020, 04:57 PM
  #1  
Junior Member
Thread Starter
 
ElCeejo's Avatar
 
Join Date: Aug 2019
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Fitting C4 ZR1s on a 4th gen rear axle

I recently bought a rear axle out of a 2002 Z28 and I've read that you have to be careful about the rims you choose to avoid rubbing. I've been looking at C4 ZR1 rims and I'm not sure what the right offset would be for the rears. I'd also like to avoid having to go at the car with a hammer to make space if possible.
Old 08-04-2020, 09:09 PM
  #2  
Moderator

iTrader: (3)
 
Abubaca's Avatar
 
Join Date: Feb 2001
Location: JAMESTOWN, NC
Posts: 8,367
Received 348 Likes on 275 Posts
Car: 1988 Iroc
Engine: L98 350
Transmission: 700R4
Axle/Gears: Hawks 8.8 - 3.73
Re: Fitting C4 ZR1s on a 4th gen rear axle

Stock rear wheels on an Iroc are 16mm offset. ....as the offset goes up, the wheels move in towards the car.
Stock 4th gen rear is wider, so stock Iroc wheels would be pushed out. ...you want MORE offset, for a stock appearance/fit. I believe 4th gen wheels are 55mm. I believe the C4 Zr1's are about 50 t0 55 as well, so they should fit, but please double check the math on all this.
Old 08-05-2020, 08:36 AM
  #3  
Senior Member
 
427seven's Avatar
 
Join Date: Jan 2019
Posts: 571
Received 482 Likes on 233 Posts
Car: 1989 Firebird GTA
Engine: Motown Aluminum 427
Transmission: TH400/GVO
Axle/Gears: Dana 44 IRS 3.75:1
Re: Fitting C4 ZR1s on a 4th gen rear axle

it's not just the fit on the rear that you need to check, you need to clear the car as well. buy (or build) a mock up tool, make sure everything clears before you put $ down on something you can't easily unload if it doesn't werk....
Old 08-05-2020, 01:24 PM
  #4  
Moderator

iTrader: (3)
 
Abubaca's Avatar
 
Join Date: Feb 2001
Location: JAMESTOWN, NC
Posts: 8,367
Received 348 Likes on 275 Posts
Car: 1988 Iroc
Engine: L98 350
Transmission: 700R4
Axle/Gears: Hawks 8.8 - 3.73
Re: Fitting C4 ZR1s on a 4th gen rear axle

Totally agree with 427, we're talking about the back, but yeah....any wheel different from stock should be measure and checked. Corvette fronts will definitely have way too much offset, though spacers will work if you feel comfortable with them. Stock is easy. Cut and dry, black and white. Anytime you deviate from stock....well.....welcome to hot rodding!!!!
Old 08-07-2020, 03:28 PM
  #5  
Junior Member

 
Camaro82Z28's Avatar
 
Join Date: Apr 2010
Location: Saskatchewan, Canada
Posts: 87
Likes: 0
Received 8 Likes on 5 Posts
Car: '82 Z28
Engine: Dart 406 ci
Transmission: T56
Axle/Gears: 3.42
Re: Fitting C4 ZR1s on a 4th gen rear axle

Originally Posted by ElCeejo
I recently bought a rear axle out of a 2002 Z28 and I've read that you have to be careful about the rims you choose to avoid rubbing. I've been looking at C4 ZR1 rims and I'm not sure what the right offset would be for the rears. I'd also like to avoid having to go at the car with a hammer to make space if possible.
I ran a full set of 17x9.5 C4 ZR1's on my car for many many years and then swapped the rears out to the 17x11s when I did the 4th gen rear. I can probably answer most of the questions you have if you need. Here's a few pictures of them on the car.





Last edited by Camaro82Z28; 08-08-2020 at 09:25 AM.
Old 08-08-2020, 01:03 PM
  #6  
Moderator

iTrader: (3)
 
Abubaca's Avatar
 
Join Date: Feb 2001
Location: JAMESTOWN, NC
Posts: 8,367
Received 348 Likes on 275 Posts
Car: 1988 Iroc
Engine: L98 350
Transmission: 700R4
Axle/Gears: Hawks 8.8 - 3.73
Re: Fitting C4 ZR1s on a 4th gen rear axle

Camaro82.....so those last pics are 17x11, WITH...the 4th gen rear? ...how do you think those 17x11 woulda worked with the thirdgen rear? Not enough clearance? That would be my guess. I swore my first Iroc would always have Iroc wheels. ....this new 88, I'm more open to different things, and I've always like the SS/GS/Zr1 wheel.
Old 08-08-2020, 02:58 PM
  #7  
Junior Member

 
Camaro82Z28's Avatar
 
Join Date: Apr 2010
Location: Saskatchewan, Canada
Posts: 87
Likes: 0
Received 8 Likes on 5 Posts
Car: '82 Z28
Engine: Dart 406 ci
Transmission: T56
Axle/Gears: 3.42
Re: Fitting C4 ZR1s on a 4th gen rear axle

Originally Posted by Abubaca
Camaro82.....so those last pics are 17x11, WITH...the 4th gen rear? ...how do you think those 17x11 woulda worked with the thirdgen rear? Not enough clearance? That would be my guess. I swore my first Iroc would always have Iroc wheels. ....this new 88, I'm more open to different things, and I've always like the SS/GS/Zr1 wheel.
Thats correct, the 17x11s were only used on the 4th gen rear, and I only had a few inches of clearance from the inner fender well. The only way they would work on a 3rd gen rear is with a 1.5 or 2 inch spacer.
Old 08-08-2020, 03:56 PM
  #8  
Moderator

iTrader: (3)
 
Abubaca's Avatar
 
Join Date: Feb 2001
Location: JAMESTOWN, NC
Posts: 8,367
Received 348 Likes on 275 Posts
Car: 1988 Iroc
Engine: L98 350
Transmission: 700R4
Axle/Gears: Hawks 8.8 - 3.73
Re: Fitting C4 ZR1s on a 4th gen rear axle

I appreciate the response, and that makes sense. ...what size tire is that up front? Looks HUGE! lol!!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
kcb
Tech / General Engine
5
01-11-2015 09:44 PM
sailtexas186548
Wheels and Tires
4
07-07-2008 01:12 PM
TKO500
Suspension and Chassis
2
06-29-2006 10:34 AM
Ramair21
Tech / General Engine
7
11-14-2005 08:20 PM
sillyiroc
Transmissions and Drivetrain
7
12-31-2003 05:32 PM



Quick Reply: Fitting C4 ZR1s on a 4th gen rear axle



All times are GMT -5. The time now is 01:45 PM.