centre bore question
Jun 12, 2018 | 09:23 AM
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 963
Likes: 57
From: Vancouver, BC
centre bore question
Is the correct centre bore for a C3 70.3? Im looking at a set of spacers and the seller said they are 70.3 centre bore with a wheel centering lip.
Jun 12, 2018 | 09:35 AM
Melting Slicks
Joined: Jan 2004
Posts: 3,245
Likes: 210
From: Detroit MI
No, it’s 70.6 for C3’s. Newer GM’s are 70.3.
Last edited by 69autoXr; Jun 12, 2018 at 02:30 PM .
Reason: .
Jun 12, 2018 | 09:41 AM
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 963
Likes: 57
From: Vancouver, BC
Jun 12, 2018 | 02:06 PM
Pro
Joined: Mar 2018
Posts: 526
Likes: 112
From: Seattle WA
Jun 12, 2018 | 02:20 PM
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 963
Likes: 57
From: Vancouver, BC
Hmmm seems like there’s not much selection online for 70.6 centre bore spacers
Jun 12, 2018 | 02:30 PM
Melting Slicks
Joined: Jan 2004
Posts: 3,245
Likes: 210
From: Detroit MI
go to motorsport-tech.com and you can order exactly what you need
Jun 12, 2018 | 03:13 PM
Pro
Joined: Mar 2018
Posts: 526
Likes: 112
From: Seattle WA
Jun 12, 2018 | 04:11 PM
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 963
Likes: 57
From: Vancouver, BC
Quote:
Originally Posted by
69autoXr
go to motorsport-tech.com and you can order exactly what you need
thanks. I sent them an email with my request
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Jun 13, 2018 | 02:04 PM
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 963
Likes: 57
From: Vancouver, BC
That place quoted me $325 for the set, a lot more than I expected for a set of spacers.
Would the attached ones work just as well?
Jun 13, 2018 | 02:37 PM
Melting Slicks
Joined: Jan 2004
Posts: 3,245
Likes: 210
From: Detroit MI
Sounds like you're looking for adapters rather than spacers. The bore on those above is too tight, you'd have ~0.002" interference at the radius. I'm not a machinist but I don't think you'd ever get it to go on.
edit: I think for a press fit you'd be looking for ~0.0005" interference across the diameter, this is approximately eight times that interference across the diameter.
Last edited by 69autoXr; Jun 13, 2018 at 02:47 PM .
Jun 13, 2018 | 02:38 PM
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 963
Likes: 57
From: Vancouver, BC
I don’t want adapters. I just need spacers to push the wheels out more since they have 6” backspace
Jun 13, 2018 | 02:53 PM
Melting Slicks
Joined: Jan 2004
Posts: 3,245
Likes: 210
From: Detroit MI
Ok, I was going from the photo you posted which appear to be adapters (1" thick with pressed-in studs).
How big a spacer do you want? I had motorsport-tech make me 10mm hub and wheel centric spacers and they charged me $70 for the pair in 2012.
Jun 13, 2018 | 02:56 PM
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 963
Likes: 57
From: Vancouver, BC
I’m looking to get 3” in the rear and 1.5” in the front. The wheels I’m getting are 18x10.5 with +25 offset and 6.34” backspace.
I need some beefy spacers to get them far out enough to fill up the L88 rally flares
Jun 13, 2018 | 03:07 PM
Melting Slicks
Joined: Jan 2004
Posts: 3,245
Likes: 210
From: Detroit MI
Quote:
Originally Posted by
titanle
I’m looking to get 3” in the rear and 1.5” in the front. The wheels I’m getting are 18x10.5 with +25 offset and 6.34” backspace.
I need some beefy spacers to get them far out enough to fill up the L88 rally flares
You need adapters to get that kind of thickness. Bolt adapters to the hub, bolt the wheels to the adapters.
Maybe check the classified ads to see if anyone has something similar for sale.
Can't you get wheels in your size that are closer to or have the correct backspace?
Last edited by 69autoXr; Jun 13, 2018 at 03:08 PM .
Jun 13, 2018 | 03:11 PM
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 963
Likes: 57
From: Vancouver, BC
Sorry I got confused for a moment. Spacers have holes for the existing studs and they just push out the wheel a little
adapters have a new set of studs which the wheels would bolt to and the adapter would mount to the car.
so yes I would need adapters. Any place to get them at a decent price?
Jun 13, 2018 | 03:16 PM
Melting Slicks
Joined: Jan 2004
Posts: 3,245
Likes: 210
From: Detroit MI
Quote:
Originally Posted by
titanle
Sorry I got confused for a moment. Spacers have holes for the existing studs and they just push out the wheel a little
adapters have a new set of studs which the wheels would bolt to and the adapter would mount to the car.
so yes I would need adapters. Any place to get them at a decent price?
Not that I know of, I haven't looked at buying adapters in almost 20 years. I bought mine at VBP but I don't think they carry them anymore, and they were probably in the $300-400 range at that time for a set of four.
Last edited by 69autoXr; Jun 13, 2018 at 03:16 PM .
Jun 13, 2018 | 03:29 PM
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 963
Likes: 57
From: Vancouver, BC
They’re selling for the same price now. But in the long run I think it will work out cheaper than getting a set of 12” wide wheels and paying for 3xx wide tires