Wheel backspacing on C3?

Reply Subscribe

Thread Tools

Search this Thread

Mar 16, 2008 | 06:49 PM

jbaron

Thread Starter

Racer

Joined: Sep 2007

Posts: 370

Likes: 5

From: Bradley Il.

2017 C3 of the Year Finalist

Wheel backspacing on C3?

I hope someone knows, Will a wheel with a 4.5 backspace fit a C3 (74) with out a prblem. The ones I want only come that way in a 15x8 unless I go custom.
Thanks Jim

Mar 16, 2008 | 06:56 PM

1981Z06Vette

Pro

Joined: Nov 2007

Posts: 741

Likes: 1

From: Woodstock GA

I'm pretty sure that the stock 15x8 Ralleys are a 4" backspacing, so you should be fine. I'd take some measurements off of your existing wheel just to be safe, though.

Mar 16, 2008 | 07:03 PM

1982CorvetteDude

Melting Slicks

Joined: Jun 2005

Posts: 2,938

Likes: 2

From: Arkansas

I have 17" rims with a 4.5" BS and I had to move the parking brake bracket on top of the trailing arm because it hit the rim in the stock location.

I think you will at least have that issue for sure

Mar 16, 2008 | 09:17 PM

Rodbuster

Advanced

Joined: Jan 2005

Posts: 77

Likes: 0

From: WAKEMAN OHIO

I put 4-1/2 backspace on and had to run 1/2 inch spacers.

Mar 16, 2008 | 09:26 PM

Glass Act

Melting Slicks

Joined: Jul 2005

Posts: 2,545

Likes: 3

From: 406ci SB, AFR 180 Heads - 490 HP @5,600 RPM 529 lb-ft @ 4,100 RPM

Pull one of your rims, lay a bar across the back of the rim, measure from the back of the rim to the bar. You will now know what the rim backspace your running now is.
I run 4.5 BS on both our 72 & 79 Vettes, no issues, some years have different issues, some must remove the emerg. brake bracket to the top, some need wheel spacers, do the quick check of what you have now

Mar 16, 2008 | 09:37 PM

GrandSportC3

Team Owner

Joined: Jul 2001

Posts: 182,997

Likes: 88

From: Lakeland, FL

Cruise-In IV-V-VI-VII-VIII Veteran

St. Jude Donor '03, '06, '17

It depends on what size tires you are using.. It also depends on your trailing arms etc..
I personally use 15 x 10 wheels with 4.5 inch backspacing with ET Drag 28 x 10.5W - 15 slicks.. However, my frame is modified for extra clearance and I'm using offset trailing arms..

Apr 22, 2008 | 08:05 PM

SpE3dF0x

Instructor

Joined: Jun 2007

Posts: 128

Likes: 0

From: San Antonio Texas

This is a REALLY good point because I would like to know if 16 X 8's are acceptable without ANYmodification? But I know I'll need to do something about it. Any suggestions other than modifing my FRAME>?

Apr 23, 2008 | 07:09 AM

StickShiftCorvette

Drifting

Joined: Dec 2004

Posts: 1,345

Likes: 3

I ran 15 x 8 wheels with 4" backspacing. I recall a stock aluminum 15 x 8 (later C3s) actually had 4.125" backspacing.

I currently run 17 x 8 wheels with absolutely no modifications. Either 245/45 or 255/40s fit well with no interfereces anywhere.