Hi All, I have a different thread on brakes on a related issue. I have a 53 Chevy with a 57 Chevy rear end and an actual real Mustang II front end suspension (the previous owner got it from a Mustang II in a junk yard). Right now it has a ford pinto brake setup 9 inch rotors for Chevy steel wheels. I've been told I should switch to an 11" setup. I've seen most GM big brake kits for the MII increase the track width by 1/2 inch per side and I've read others up to 1 inch. ECI makes one that claims to not increase track width at all. Does anyone know if increasing track width by 1" per side would be an issue? I'm not even sure if there would be track width increase over the rotors I have now. I have seen some of the firewall/side wall polished by the tire so increasing the track width a little may actually make that go away but i dont know if it would rub on the fender on a turn. I've made it a point to never make a u-turn ever. Thanks!
one of the problems with 11 inch rotors on a real mustang front end is the rotors rub the lower a arms when the brakes are applied so you have to relieve the edge of controlarm. now having said all that mine is a 41 ford pu with the 11inch conversion. my brother in law has a 40 ford pu with mustang brakes with 5 lug rotors and itstops just as good as mine with the big conversion.
The original MMII track width is about 56". Your Chevy is, I believe, closer to 59"/60". Studebaker46 is correct about potential interference with the larger rotors, but it can be safely dealt with. Ray
After you correct the rotor/control arm rub, you will need larger wheels to fit over those bigger brakes. So my question is are you driving on a road or a road course? Just having disc brakes and self adjusting rear brakes are WAY better than the old drum brakes alone.
Thanks. What is the best way to relieve the control arm? I am hoping I can upgrade to 11 inch. I'm more or less a novice with metal fab type work.
Thanks. So the stock Chevy steel wheels won't work with 11 inch rotors? I am driving on normal roads except steep hills make that car really hard to stop. The current setup is 9" ford pinto disc brakes on that mustang II front end. The rear is a stock 57 chevy with 1" bore wheel cylinders. I measured 5.2 to 1 ratio on the brake pedal ***embly and it has a 70s ford mustang master cylinder with a 1 inch bore I believe (I forgot to measure the bore diameter) Right now the pedal goes straight to the floor so I suspect a bad M/C. Since I'm going through all this work I thought of changing to 11" and maybe a different M/C. Any advice?
If I remember correctly you will have to take a grinder to the outside lip of the control arm. A couple of licks in the right spot with a BFH might work but that won't help alignment any. I'd play it by ear knowing that I was going to have to rework that outer part of the control arm a bit and work at getting the clearance I felt I needed which isn't an extreme amount. You want it to fit all through the travel of the suspension though. As far as wheels, you have 15 inch wheels but I think they are the original wheels and you will probably need a spacer to move them out just enough to clear the calipers. I'd start trying the wheel with no spacer and then use flat washers on the studs to space the rim out maybe 1/4 inch to see if it cleared the caliper. When you figure out what thickness works you can buy "disk brake spacers" at just about any tire store or get them though parts houses. If you have pressure on the master cylinder and feel it sink to the floor as you hold it I'd say the master cylinder is byp***ing and needs to be replaced.
Thanks so much. It seems the 11" rotors will move the wheels out to begin with and adding a disk brake space may move them out even more. I'm not sure if the wheels would run. The front is lowered with cut springs so the increasing width may be a big issue.
the easy way to relieve the control arms is with a grinder but if you are just doing normal highway driving change the master cyl and drive it like I said my brotherinlaw has basically same truck as me except more hp and he drives it hard and it stops just as good as mine does with 11inch brakes when ibuilt mine I needed rotor and calipers and it was just as cheap to upgrade to the big brakes as it was to buy new stock calipers and 5hole rotors
Thanks, that will be my starting point. I'm going to get 11" in brake kit and grind the control arm a little. I'll replace the M/C since I suspect it is bad. It has a 67-72 ford mustang M/C with 1" bore. It has the stock 53/54 pedal from what I can tell.
I did the 11" swap on my '53 with a Mustang II front end. I used Granada rotors with a GM bolt pattern. When I first did the swap I ground the end of the control arm. The end of the arm started to get a little thin and I got nervous so I got another set and reshaped it with heat and a hammer. Even then, I still had a little rub on the rotor. The issue with altering the control arm I had was having to alter the lower ball joint as well. I didn't want to brake down away from home and have to deal with altering and replacing a ball joint on the road. I ended up getting a set of tubular lower control arms from a guy here on the H.A.M.B. with the screw-in ball joints. It completely fixed my clearance issues and I feel more comfortable with the setup.
Thanks, that seems complicated. I wonder if the position of the rotors change will change much? It seems where my 9" rotors sit right now, there wouldn't be an interference if I project out with a straight edge, but I don't know how far in or out 11" rotors would shift. I have a real mustang II front end not from a kit so I'm worried on changing any control arms, etc and opening up a can of worms. Hmmm. Here are photos showing that my 15" rims should handle the 11" rotors and a view of the control arm/9" rotor
I would think that the chrome ones would be a direct bolt in and give you clearance. I have the "a arm" style and had to weld on some gussets.
I usta have a '39 Chevy that I installed a Mustang II front end in, using the stock MII crossmember. I used dropped spindles from Heidts, and a large disk brake kit that used some Camaro rotors. I don't remember having to grind any on the lower control arm. The time it will interfere is when the weight is on the tires, not jacked up like in your photos. You will just need to ***emble the parts, get it off the jackstands, and stick you head underneath while somebody turns the steering wheel back and forth. All this guessing won't give you a solid answer.
The extra inch or so spacing per side will actually work quite well. And it will get the inside of your wheel away from the control arm. I have an actual mkII Front suspension on my 53 Chevy, and I originally put it together with wheels that had extra front spacing to get the track width of the '53 Chevy track width. Looked good, drove fine.
Thanks. I will just buy an 11" kit and see how it all fits together and then look at what needs to be ground out.
I finally got to this. I bought the Speedway 11" Disc brake kit. I noticed the wheel moved out by 3/4" to 1" I did just a quick configuration check but have not greased bearings, bled brakes etc.. I have 2" dropped spindles and it looks like my turning ability hasn't reduced a whole lot from before but it's hard to tell. The photos show the max I can turn the wheel. I hope it's enough for a right hand turn at a light. I'm moving from my house next Sunday and will be in a 1 car garage so I'm hoping I get lucky and I don't have huge surprises if I install the kit and drive it on Saturday or I'll be screwed. I noticed the 11" GM rotor clears the control arm so I shouldn't need to grind it (The 11" granada one was closer from what I remember than the Chevelle ones in the photos below). It's hard to tell from the photos but I measured at least 3/8" gap between the control arm lip and rotor during the entire wheel position when turning and also with the car on the ground and on jackstands. The caliper is the GM intermediate which is bigger than GM metrics and does not rub on the rim and it clears the stock Mustang II strut bar. I'm encouraged enough to give this a go. Does anyone see anything obvious I'm not taking into consideration? The other 11" disc brake kit I bought had GM metrics and Granada rotors but I decided to install this one. It should be a big improvement over the stock pinto brakes. I also installed a new 68-72 Mustang Master Cylinder with 1" bore.
Thanks. Haha yep on a scary tight deadline. I will hopefully bolt/install all of it on Saturday and drive it (fingers crossed it doesn't rain here as predicted). If it doesn't work out I have Sunday to put the old set up back together and drive it down to San Diego where it's staying in a 1 car garage. No big projects on this for a few months until I find a better place to work on it.
The Jalopy Journal
