Small bolt pattern disc upgrade

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Don't know the quality but it looks good and the price is reasonable.
 
That "kit" has been discussed before, here on this site.
The guy is buying rotor "blanks" and just drilling them out for the small, 4" inch bolt pattern.
But, as the description states, you gotta make sure they will fit the wheels that you presently have.
Personally, i don't feel that it's a bad deal, in what you would be getting for the $$$$$$.
 
That kit is just a 73+ factory disk kit with rotors that were drilled for 5x4” and possibly with a center hub that was turned down. Looks like the same kit that pirate jack was selling.

I’m going to go out on a limb and say the source of the rotors is the same, so you may have issues. Just do a search on the pirate jack kits, people have had issues with the rotors being out of round.
 
Make sure you know what Car the parts are intended for or you might have issues in the future finding replacement parts.

This is just my 2 cents.... there is no reason to cross drill vented rotors. (sure if you are doing road racing and hitting the brakes hard maybe there is a benefit)
 
Make sure you know what Car the parts are intended for or you might have issues in the future finding replacement parts.

This is just my 2 cents.... there is no reason to cross drill vented rotors. (sure if you are doing road racing and hitting the brakes hard maybe there is a benefit)

The only trick will be the rotors themselves. The rest of it is all 73+ factory disk brakes- spindles, calipers, wheel bearings, caliper mounts, brake pads, hoses etc are all stock 73+ Mopar.

The rotors could be replaced with off the shelf 73+ rotors too, but they’d be 5x4.5”. So if you wanted to stay SBP later, you’d have to custom machine 73+ rotors if you couldn’t source them from this supplier.
 
That kit is just a 73+ factory disk kit with rotors that were drilled for 5x4” and possibly with a center hub that was turned down. Looks like the same kit that pirate jack was selling.

I’m going to go out on a limb and say the source of the rotors is the same, so you may have issues. Just do a search on the pirate jack kits, people have had issues with the rotors being out of round.


I have a
The only trick will be the rotors themselves. The rest of it is all 73+ factory disk brakes- spindles, calipers, wheel bearings, caliper mounts, brake pads, hoses etc are all stock 73+ Mopar.

The rotors could be replaced with off the shelf 73+ rotors too, but they’d be 5x4.5”. So if you wanted to stay SBP later, you’d have to custom machine 73+ rotors if you couldn’t source them from this supplier.

Ya...good point. Supplier says he will not sell rotors separately.
Yeesh. Keep thinking I should just switch to lbp already....
 
Only reason I would stick with the small pattern would be on a high end restoration. Other than that, big pattern all the way.
 
Only reason I would stick with the small pattern would be on a high end restoration. Other than that, big pattern all the way.
Ya..i guess i was thinking i was trying to save funds for other parts for it because I had rims and rear end small bolt so...but long run, I think your right...
 
Ya..i guess i was thinking i was trying to save funds for other parts for it because I had rims and rear end small bolt so...but long run, I think your right...

You can do the B body axles and brakes for the rear.......it would be cheaper than the brake kit by far. Then you could do the 73-76 stock A body disc upgrade. Just a thought.
 
cuz they 'wont fit 14" Year one Ralleys'. Are they any different than Mopar Ralleys? Looks pretty good to me. Im not hip on the cross drilling of the rotors. Seems it would eat the pads faster but even stock rotors are hard to find today.
 
Not sure of the compatibility to your car but why not switch to KH stock front discs 67 - 68- 69? SBP

I have seen the entire setup, spindles etc here for reasonable price.
 
cuz they 'wont fit 14" Year one Ralleys'. Are they any different than Mopar Ralleys? Looks pretty good to me. Im not hip on the cross drilling of the rotors. Seems it would eat the pads faster but even stock rotors are hard to find today.

They won’t necessarily fit factory SBP wheels either. The center hub is larger on the ‘73+ rotors. In those kits the center hub is machined down, but it’s still a larger diameter than the hubs on the KH rotors.

And, that also means the wall thickness on those hubs is quite a bit less than stock. Granted the factory design was likely overkill, but who knows what kind of calculations were done on those rotors with turned down hubs.
 
Not sure of the compatibility to your car but why not switch to KH stock front discs 67 - 68- 69? SBP

I have seen the entire setup, spindles etc here for reasonable price.
Expense. KH used runs 3-350 the you need to machine rotors or buy new...500 all new seemed too good to be true, hence my initial question. Im new to all this so I figured Id ask u guys..
 
More I think about it...large bolt seems better evertime I discuss it. I will have to look into a B body axle setup that Ratrod suggested Im guessing.
 
I used the set up from SSBC. Rotor can do small or big bolt pattern.

Top notch stuff. You will pay a bit more but when it comes to brakes saving a few buck might not be the best thing. IMHO.

ssbrakes.com
 
Have you checked out dr diff? He sells some kits but not sure if anyone has used them or experience with them.
 
If you go to BBP just call DoctorDiff. He sells a real 73+ Mopar kit that uses all reproduction parts, so when you go to do a brake job you can just go to the local auto parts store. The 73+ Mopar brakes work great, they used them for decades and on cars that weighed a lot more than A-bodies.

The SSBC kits work fine but then you’ve got the same problem, some of their parts are made only by them and you’d have to get your brake job parts from them forever. And the brakes don’t really outperform the 73+ Mopar stuff.

DoctorDiff is a great guy, his parts are top notch. And Cass is super knowledgeable and his customer service is great. I don’t use his stock 73+ kit, but I do run his 13” rotor kit on my Duster. Great stuff. If you use the 73+ parts and want to go 15” rims, you can even use the 11.75” rotors that came on the later B/R body cars. Again, all stock parts, and doctordiff sells it all in one kit. All stock design parts, and a nice little upgrade over the 10.98” rotors.
 
Last thing I'll say about keeping the stock parts. A bunch of engineers worked out the calculations for the stopping power of the front brakes and the rear brakes and designed the correct portioning valves to get the best stopping distance in the safest manner. Can aftermarket or Frankensteined parts do a better job ... maybe, but there is a lot of trial and error and maybe extra parts and in the end who knows!
 
Last thing I'll say about keeping the stock parts. A bunch of engineers worked out the calculations for the stopping power of the front brakes and the rear brakes and designed the correct portioning valves to get the best stopping distance in the safest manner. Can aftermarket or Frankensteined parts do a better job ... maybe, but there is a lot of trial and error and maybe extra parts and in the end who knows!

Yeah, but keep in mind that those engineers worked out the calculations figuring that the tires on the car would be a set of rock hard bias ply's that had a tread width of like 6". And they did it in the 70's, when the available technology was completely different.

The logic that "factory engineers designed it so it must be better" doesn't hold up at all. That was over 45 years ago. There's all kinds of things the factory engineers totally dropped the ball on if you're talking about comparing original parts to modern aftermarket parts.

I like the 73+ disks, they do work pretty well. I think that for the way most of these cars are used nowadays they're plenty good enough. In fact they worked well enough that Chrysler used the same exact brakes all the way up until 1989 on some models, on cars that were heavier than the A-bodies ever were. So that particular design actually held up pretty darn well. But that's just this particular case. If you said that the factory engineers did the calculations and found that a 100 lb/in torsion bar was a good idea- so it must be a good idea, I'd tell you the factory engineers totally pooched it on that one, because they did. That wasn't even that great in the '70's with bias plys, and it's a total mess with radials, even period correct stuff like BFG T/A's. So in that case referring back to the factory calculations is a terrible idea.
 
The Kelsey Hayes 4 piston disk work quite well on the track too. Pads are easily available in all flavors.
 
well cross drilled rotors , just more edges to release the heat from , it might help with wrap edge as well .
 
i just spent some time reviewing the 4'' bc disc brake packages , the stock k/h is the only one that is able to mount the stock steel 14'' rim on . most of them require a rim change or 15'' rims . so i'm going to stock k/bs on my a bodies , and keeping that oddball 4'' bc as well . as long as i can get the replacement parts .
 
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