The bracket is shorter on the V6 calipers.  By same design, the caliper bracket on the 05-2010 GT 12.5" brakes are shorter than the brackets on the 2011 and newer 13.2" brakes.  Calipers interchange on all three.

Before you get ideas of using the V6 calipers with my GT2008-FT brackets, the drum hub will not fit inside the hat section in the back of the V6 rotor.  If you machine it down, the margin around the wheel stud holes get smaller than they should be.  The later model hubs fit in there with the same bolt pattern because the wheel studs have a much smaller knurled section, only 0.56" diameter, vs the early hubs using 0.620" or larger.  Also, the late model hubs are thicker material and are steel rather than cast, making them much stronger.

The margin is the distance between the edge of the stud hole and the edge of the hub.  If it is too small, you risk cracking the hub, possibly releasing the wheel and creating havoc and an unsafe condition.  This would be an issue with a bolt that simply goes through the hole, but is even worse when you have a pressed fit which tends to try and expand the hole.

You CAN use either the 12.5" or 13.2" GT brakes without issue.  With those rotors, only a very small amount of the hub must be ground down or machined off for it to fit inside the larger rotors.

when I was completing my 05 brake setup, I found by accident that I had been given 05 gt discs with 05 v6 calipers....wouldn't bolt up,,...I was cursing for some time before I figured it out.

It's only the brackets that are different...the calipers between the v6 and v8 cars are the same.  If you already have v6 calipers, you can score the v8 discs and brackets and you'll be good.  I verified this also by looking at the caliper part numbers side by side, v6 vs v8

The calipers for the V6 and V8 are not the same, the mounting holes on the V6 are off from the area that they are on the V8 calipers. If you interchange them on the same bracket one will sit higher than the other. I'll see if I can dig out one of each to post a pic later.
Jon

Jonk67 wrote:

The calipers for the V6 and V8 are not the same, the mounting holes on the V6 are off from the area that they are on the V8 calipers. If you interchange them on the same bracket one will sit higher than the other. I'll see if I can dig out one of each to post a pic later.
Jon

I think you're confusing the caliper bracket, the part that carries the pads, and the caliper. The caliper piston assembly is the same from 2005 to current generation. It is only the caliper bracket that is different. Moving up from smaller to larger rotors it will be a taller part to move everything further out from wheel center so that the pads land at the right place on the larger rotors.

2005-2010 V6 cars used 11.5" rotors and 2011-2013 V6 use 12.4" rotors (which were the GT brakes for 2005-2010). 2005-2010 GTs used 12.4" rotors and the 2011-2013 GTs use 13.2" rotors.

So 11.5" V6 rotors and associated calipers will come with a shorter caliper bracket, the current 13.2" rotors will use the tallest bracket with the 12.4" rotor brackets falling somewhere in between the two in terms of height. All of these brackets use the same spacing for the mounting holes at the spindle & caliper attachment point.

For the OP, per MustangSteve it sounds like the only real problem with using the smaller 11.5" rotors (and the correct matching caliper bracket) is that the drum hub won't fit inside of the smaller 11.5" rotor without having to remove too much material from the hub O.D. to be safe. If you've got good calipers from a V6 you'll just need to find a set of brackets to use them with the 12.4" rotors.

Last edited by McStang (6/19/2013 3:40 PM)

McStang,  What's with that ball joint stud?

I was just going to go with 05 mustang gt front brake set up on my 65 but I found a great deal on some 2011 mustang gt rotors pads calipers and caliper brackets all for 100 bucks plus shipping. All else I need to get is the mustang steve drum spindle bracket can't wait till I'm braking.

True74yamaha wrote:

I was just going to go with 05 mustang gt front brake set up on my 65 but I found a great deal on some 2011 mustang gt rotors pads calipers and caliper brackets all for 100 bucks plus shipping. All else I need to get is the mustang steve drum spindle bracket can't wait till I'm braking.

That's exactly what I did 'cept I got fronts & rears for $225. Everything fits perfectly with Steve's  brackets front & rear. I put Hawk HPS pads on all around and the car will definitely stop!

McStang wrote:

MustangSteve wrote:

McStang,  What's with that ball joint stud?

It's a big Moog screw-in ball joint with the perfect taper for '65-73 Mustang spindles (these are '71-73 spindles on the '66) but the stud is a little longer than it needs to be so there's a 4130 spacer to get the castellated nut to line up with the cotter pin hole. In that pic everything was just finger tight for fitment. Here's one with everything properly bolted up, torqued and on the ground:

 OK, I see.  It is a custom ball joint.  Looks good.

Looks like a way to use same ball joint no matter what size the spindle hole is.  Much cheaper to supply a different spacer for each application that it is to supply a different ball joint!

I would want the front brakes to apply before the rears.  My vote is proportioning valve.  What are the qualifications of those who say you do not need one?

Heck, you can drive without rear brakes at all if you want.  I drove a Mustang from Illinois to Texas with NO REAR BRAKES.  It did have a proportioning valve though!

So I purchased some 2011 mustang gt calipers rotors and pads new on eBay for only 100.00 great deal. So I'm courious though. Do I have to machine down the od of the drum hub to make the rotors fit? Because the pilot hole is pretty small

I'm just courious yes I'm meant the pilot hole i was told its to small to fit over the drum hub so I'd have machine it a bit to get it to work