#1  
Old 05-30-2019, 11:44 AM
leecorrell leecorrell is offline
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Default 67 disc brake upgrade - C3 corvette rotors?

I've been researching for a drum to disc brake upgrade on my 67 Lemans for years now. I upgraded to 15" rally II wheels a couple years ago in prep for this upgrade, so my requirement is that is must fit with those wheels. I was going to just go with a stock 69-72 style swap, but started to find that I could get better brakes for less money if I plan this out well.

I found a popular swap is 98-up F-body rotors and calipers with drum brake spindles and hubs using a custom mounting bracket. I happened across a 2000 f-body while at the salvage yard a while back, so I grabbed the calipers and rotors for cheap. I knew that there was a high likelihood these would not work with the 15" rally II wheels, and that is the case. The calipers protrude beyond the hub face where the wheel mounts and that is a problem. Diameter wise it does look like they will fit inside the 15" wheel.

I started looking for rotors that would allow me to space the calipers further inboard and came across some discussion around using C3 corvette rotors (11.75" diameter and 1.25" thick). It looks like this was even an option on 68-69 Camaros known as the J52 and/or JL8 brakes? Since the Camaro uses the same spindle it seems like this might be an option. I even cam across some old discussions on this site while searching where it looks like Scarebird was working on a kit that used the C3 rotor. However it was 10 years ago and I don't see such a kit listed on his website.

I'm curious if anyone has done a disc brake swap using the C3 corvette rotor and if you can give me any guidance on doing so? I would like to use the 98-up F-body caliper still if possible since I already have them and they are aluminum monster size PBR calipers (I realize I'll have to make my own custom brackets to do so). Otherwise it looks like an 80's GM truck caliper might be my next best option. Short of tearing my car down and rendering it undriveable until I complete the swap, I'm not sure how to proceed at this point. I feel like I need the measurement from the drum hub face to the spindle brake mounting surface to figure out if I can make this work, but have been unable to find that measurement listed anywhere on the internet. I'm just about to buy a spindle and hub just to mock this up with.

Any advice?

  #2  
Old 05-30-2019, 12:46 PM
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Scarebird Scarebird is offline
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Location: ABQ, USA
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Quote:
Originally Posted by leecorrell View Post
...I even cam across some old discussions on this site while searching where it looks like Scarebird was working on a kit that used the C3 rotor. However it was 10 years ago and I don't see such a kit listed on his website.

Any advice?
We dropped the C3 rotored setup as it required a custom hub and drove the price above a point where it was competitive.

We did however develop another heavy duty variant that is similar in size but can reuse the stock drum hub and spindle. We use the 90's GM truck caliper and Jaguar rotor to do this.



  #3  
Old 05-31-2019, 03:59 PM
leecorrell leecorrell is offline
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Scarebird, what are the specs on that rotor / kit? I don't see the specs listed on your website, am I missing it? Perhaps a parts list or instructions so I can look up and price out the parts? The C3 rotor is appealing to me because the 11.75" diameter and 1.25" thickness is a significant upgrade over the stock 11" x 1" rotor. The 1.25" thickness also happens to be compatible with the f-body calipers I have.

  #4  
Old 05-31-2019, 09:21 PM
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Scarebird Scarebird is offline
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these are the specs:

Bolt Circle Diameter 4.75 in
Bolt Hole Quantity 5
Center Hole Diameter 3.15 in
Directional or Non-Directional Non-Directional
Discard Thickness 1.07 in
Height 2.64 in
Outside Diameter 11.460 in

It will NOT work with F-Body calipers. We supply a centering ring for the rotor.

  #5  
Old 10-30-2019, 12:33 AM
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bignate bignate is offline
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To use c-3 Vette rotors you need to use disk brake spindles and drum brake wheel hubs with longer studs. I welded up and redrilled my caliper brackets and used the ‘81-‘91 half ton truck calipers. Make sure calipers are for 1.25” rotors as the half ton trucks were available with 1” rotors also.

I have this setup on my Judge right now, stopping power is greatly increased and fade resistance is much better.

Nate

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