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blksn8k
10-14-2002, 06:56 PM
I would like to install the factory wheels from my 99 Cobra onto my 89 SC. I have found several companies that say they can make an adapter to do this. I read the thread from back in May and it seemed like everyone had a different opinion. Some said to have the wheels redrilled and others said to try adapters. Has anyone actually tried either method? I do not want to redrill as I might want to put these wheels back on the Cobra someday. The Cobra wheels are 17x8 with approx 6" backspacing. Most of the adapters are either 1" or 1.2" thick. The SC is not here right now so it's not possible to measure it's wheels. Could someone tell me the backspacing on an 89 SC wheel? Thanks! :)

gldiii
10-14-2002, 09:03 PM
The stock backspacing is 5.54". The 9" Cobra R replicas that many people run are 6.42".

I am not a big fan of wheels adapters of any kind. On the SC it is fairly easy to upgrade to the Mustang 4.5" bolt circle by using Mustang hubs in the front (a bolt on) and either re-drilling or using the IRS Cobra hubs in the rear. I have the 'Stang hubs on my car and the 13" Cobra brakes up front and larger Cobra rotors in the rear as well.

If you are interested here a link to Doug Fraleigh's article on the bolt circle change.

http://members.bellatlantic.net/~fraleigh/Article.html

blksn8k
10-16-2002, 07:27 PM
Thanks, George. Since my car is an 89 the "bolt on" part gets a little more involved. Not sure I want to get into replacing spindles. Sounds like the easiest solution would be to buy the 17x9 Cobra R replica wheels in the 5x4.25 pattern.

gldiii
10-16-2002, 10:26 PM
Actually, the Mustang hubs bolt on the 89 spindles with no problems. It is just the caliper upgrade that requires the newer spindles. To keep your stock SC brakes you would only need to re-drill the rotors. On the front, I believe that if you needed new rotors, the Mustang GT rotors would fit. (I'll have to verify that one!)

If you just want the Cobra "R" look, then wheels with the TBird bolt pattern would be the easiest. If you want to open up the possibilities for many different wheels, then the 'Stang bolt circle changeover really expands your choices.

fast Ed
10-16-2002, 11:13 PM
The 89 - 90 rotors have the smaller hub hole, so you couldn't reuse stock rotors with the Mustang hubs ... you would need to either get 91 - 97 Bird rotors and have the bolt pattern redrilled, or 94 - up non-Cobra Mustang rotors.


cheers
Ed Nicholson
SCCoO

intercooled89xr
10-16-2002, 11:38 PM
u can get the cobra rims that fit right on your car at this site i dont know if u know or not custom wheels market.com

blksn8k
10-17-2002, 05:45 PM
Great info guys! I just want to make sure I have this straight. If I wanted to use the wheels from the Cobra it sounds like on the front I can replace the T-bird rotors with rotors from a Mustang GT and no other changes, right? I would need to buy new bearings and retaining nuts but that's it, right? I also understand that if I want bigger brakes I would need to install the spindles from a 93 or newer 'Bird and the rotors from a Cobra or Bullitt, etc.
On the rear I have several choices. First, I could redrill the hubs to the 5x4.5 pattern. Second, I could replace the stock hubs with those from a 99 or newer Cobra which would also allow me to install bigger rotors. Or, I could use adapters, which not many people seem to think is a good idea. I'm not totally convinced of that, especially if they are made from something other than cast aluminum. There could be a clearance issue with the body at the outside as the adapters would need to be about 1" thick.

gldiii
10-17-2002, 06:03 PM
That's pretty much it, new hubs, hub nuts and rotors on the front and either redrill or Cobra IRS hubs out back.

One thing that may not be clear is that you will also need new lug nuts for the conversion. The SC nuts are 12mm the 'Stang are 1/2" ones. New locking nuts as well (if desired). Also, your SC spare will no longer work!

The brake upgrades on the front require the 93-up spindles with ABS and new swaybar end links. On the rear you would use your stock SC caliper with an adapter on the bigger Cobra rotors.

fast Ed
10-17-2002, 06:26 PM
Originally posted by blksn8k
On the rear I have several choices. First, I could redrill the hubs to the 5x4.5 pattern. Second, I could replace the stock hubs with those from a 99 or newer Cobra which would also allow me to install bigger rotors. Or, I could use adapters, which not many people seem to think is a good idea. I'm not totally convinced of that, especially if they are made from something other than cast aluminum. There could be a clearance issue with the body at the outside as the adapters would need to be about 1" thick.

The Cobra hubs only allow you to use 5 on 4.5" b.p. wheels, which accomplishes the same thing as redrilling your stock hubs ... for the brakes, you need to either redrill the stock T-Bird rotors for the same b.p., or go with the Cobra rotors, and fabricate the adapters to move your stock calipers up and over to clear the bigger diameter, different offset rotors. Doug's site has the instructions for that too. Unfortunately base model Mustang rotors won't work on the rear as a bolt-on because of the difference in hat offset, and the calipers have a different parking brake cable attachement.

cheers
Ed N.