Rear brake rotor 4.5" conversion?

[RRRCobraSC281]

I've tried searching for info on what rotors to use on the rear for a 5 x 4.5" converted hub. This is on a new build and, if possible, I want to keep with the stock Mark VIII calipers in the rear. Don't really want to use the Cobra calipers, since the e-brake cable is slightly different.

I wonder if the 94-04 Mustang GT rear rotors are the same size as the Mark VIII?

Any help with this info would be nice.

Oh...and one more thing... This is going on a FFR Cobra replica using the VIII knuckles and mounted with 15" rims. Plans are to not go Cobra 13" rotors up front since 15" rims will not clear the front calipers.

Robert

 

[mafioso]

Use the Mark VIII rotor re drilled to 5x4.5. with the cobra hub

 

[RRRCobraSC281]

I thought of that, but I really don't like the idea of redrilling rotors everytime it needs to be replaced.

Somebody here has done this. Or do most people just jump up to the Cobra rear calipers and use the adapter brackets?

 

[RRRCobraSC281]

update

I guess the rotor diameters are not the same for the Mark VIII 10.3" and 94-04 Mustang GT 10.5". I guess it's been said that in order to use 94-04 Mustang rotors, you need to use the Mustang calipers. The only way to use the Mark VIII rear calipers with the 5 x 4.5" hub is to redrill the rotor as you suggested.

 

[phreakness]

I used rotors from a 2003 Mach and reman'd Mark VIII calipers. But remember you'll need the brackets to move the calipers and a little grinding on the mount (can't think of what its called at the moment)

 

[lscmkviii]

That what I did too phreak! Its a simple job with good results. worth it!

 

[MarkVIII93]

I thought of that, but I really don't like the idea of redrilling rotors everytime it needs to be replaced.

Somebody here has done this. Or do most people just jump up to the Cobra rear calipers and use the adapter brackets?

I did it and everytime they're replaced?? You wont need to replace them for at least 30k miles. There isnt another rotor to work with the stock calipers on stock mounting positions.

 

[chicken]

nice cobra!

 

[Staffamerica74]

I redrilled my rear rotors, when they are shot im gonna get the mounts and go with cobra rotors.

 

[RRRCobraSC281]

After looking at our options, we're going to buy the slotted and cross drilled rotors for the VIII and re-dril them with the hubs to 5 x 4.5"

The cobra caliper pistons are actually smaller than the ones on the VIII. So caliper performance actually is better with the VIII.

Thanks to all that responded.

Robert

 

[driller]

FYI - for those who don't know...

MN-12 BoltCircle change and brake upgrade.

 

[Icarus]

After looking at our options, we're going to buy the slotted and cross drilled rotors for the VIII and re-dril them with the hubs to 5 x 4.5"

The cobra caliper pistons are actually smaller than the ones on the VIII. So caliper performance actually is better with the VIII.

Thanks to all that responded.

Robert

If your 5x4.5 already (which it sounds like,) buy the Cobra rotors, and make or buy the brackets to use the Mark VIII calipers as in the link driller posted, and the pics phreakness put up. It will save you the hassle of having the rotors redrilled as the brackets are cheaper/easier to do. You can then keep the e-brake and have the bigger pistons. Fast Ed sells the brackets you need and is a great guy to deal with, or make your own...
By far the easiest way to do it imho...

 

[RRRCobraSC281]

I'm asking these questions for a fellow builder. We are just trying to keep it simple so he's having the hubs and a new set of rotors drilled to 4.5". He's running 15" wheels so will not be using the Cobra brakes up front.

The plan is to use Mustang GT brakes up front and Lincoln Brakes in the rear.

I plan to go with the Brembo 14" on my FFR and using the 13" Cobra brakes on my 60 Ranchero, which has the Mustang II 11" disc up front at the moment. There's a guy selling Cobra brake conversions for Mustang IIs on eBay, but $260 is a bit steep for a bracket and a bag of grade 8 bolts. The strange thing is that it requires the use of drum hubs to make it work. Haven't seen too many of those.

Robert