Pirate Jacks disc brake conversion kits

-

RON REAGLE

FABO Gold Member
FABO Gold Member
Joined
Jul 31, 2019
Messages
964
Reaction score
3,015
Location
BEAVER FALLS PA
I'm looking at Pirate Jacks for a disc brake conversion for my 68 with 4" bolt pattern wheels and 7/16 studs ( I don't want to convert to 4-1/2" bolt pattern and lose "the look" the centerlines on it give the car)
Has anyone used their kits and are you happy with them? Is there another kit out there that you can retain the 4" pattern and 7/16" studs? Most of the ones I can find upgrade you to 4-1/2" bolt pattern with 1/2" studs.
 
I'm looking at Pirate Jacks for a disc brake conversion for my 68 with 4" bolt pattern wheels and 7/16 studs ( I don't want to convert to 4-1/2" bolt pattern and lose "the look" the centerlines on it give the car)
Has anyone used their kits and are you happy with them? Is there another kit out there that you can retain the 4" pattern and 7/16" studs? Most of the ones I can find upgrade you to 4-1/2" bolt pattern with 1/2" studs.

Avoid them, and call Dr Diff instead. I helped a buddy try and install them on his GM convertible. They bolted on with some issues on alignment, fit and then we found out they sent the wrong power booster bracket. They looked good on paper, but don't live up to claims or even function properly.

Customer service was good for the first few calls for help and resolution, but quickly degraded to adversarial and unhelpful.

His brakes now pull when he stops (4 wheel discs with a distribution block), and there is no resolution in sight. He is now looking to switch over to Wilwood brakes.
 
I second calling or emailing Cass (Dr.Diff). He will set you straight on what you need and support any questions. Super great guy, couldn't ask for a better vendor.
 
Hey Ron I did use the Pirate Jack kit on my 66, if you look up my post "ordered my disc brake conversion kit today" everything about the kit including all my pictures and all the good and bad comments that you will need are in there. I thought the kit was great and the price was great also. A lot of members had their pro's and con's about the kit but I was very happy with it and it was very easy to install and yes I did keep my small bolt pattern wheels this was one of the reasons I went with the Pirate Jack kit. The only thing that I noticed was that I lost a small amount of turning radius with the kit but nothing that I can't live with.
Bob
 
Yeah I put it in my 66 and fit and works good. Needed some fittings and things but all was easy to find.
Andrew
 
I put Wilwoods on my '70 duster and you can run either small or big block pattern money WELL spent!!
 
im running scarebirds on my 71

all off the shelf consumables (discs, pad, and even calipers) as long as you dont that some of it came from a chevy citation, some from a toyota of sorts and i believe the hoses were even off a cadillac or something

back when i bought it, the "whole package" was about 500 but you can probably knock an easy 200 of it scrounging the parts yourself
 
I'm not a fan of using the drum brake spindles and converting to disc like some kits offer. I want new spindles and everything to work and fit properly (no issues after installation) I know Wilwood makes a great product I just haven't found a kit that's complete including spindles.
 
If you would have looked at my thread you would have seen that the Pirate Jack kit comes with new spindles, they include a crush sleeve so you can stay with the small ball joint to fit your small bolt pattern.
Bob
 
I looked and I realize those kits do come with the spindles. That's one of the reasons I looked at Pirate Jacks in the first place "one stop shopping". I plan on upgrading to a large ball joint upper control arm to avoid the crush sleeve or adapter on the small ball joint uca. When you look at the Wilwood kits they don't show spindles and some kits out there adapt a drum brake spindle which I don't want to do. I really appreciate your efforts to answer my question Thanks
 
I have had the SSBC A153 kit on my '71 Dart GT for about 15 years now and I'm completely satisfied with them. I too chose them so I could keep the small bolt pattern wheels as well (I have a factory installed 8 3/4", 3.23:1, 741 sure-grip rear end).

FYI, the factory 14" X 5 1/2" Rallye wheels fit perfectly. However, the 14" X 5 1/2" steel wheels do NOT fit.
 
I'm not a fan of using the drum brake spindles ...
When you throw in a random requirement like that, your choices shrink to almost nothing. True, many kits (Dr. Diff, etc) are based on 1973+ factory disk parts, including its spindle, but I doubt an earlier drum hub with 4" bolt pattern can fit that spindle. Maybe if you found proper-sized wheel bearings, but never heard of that. The 1973+ hubs are integral with the rotors. Perhaps you could re-drill a rotor for 4" bolt pattern, but never read of such.

What scares you about a drum spindle? They are forged, and never heard of one failing. Definitely prefer the 10" drum spindle since beefier and its hub uses larger wheel bearings (SET2 & SET 6). The small bearings in the 9" drum hub can fail (SET 1 & SET4). Indeed, you are better with a drum spindle than the rare disk spindle since most kits bolt to a drum spindle. The SSBC W153 kit bolts to a 10" drum spindle. I wouldn't chose that since it uses the now-rare K-H calipers and rotors. Your best choices to keep your 4" bolt wheels are Scarebird and Wilwood. Scarebird is only ~$120 for brackets and you can source calipers and rotors cheap locally (Toyota & Chevy parts).
 
When you throw in a random requirement like that, your choices shrink to almost nothing. True, many kits (Dr. Diff, etc) are based on 1973+ factory disk parts, including its spindle, but I doubt an earlier drum hub with 4" bolt pattern can fit that spindle. Maybe if you found proper-sized wheel bearings, but never heard of that. The 1973+ hubs are integral with the rotors. Perhaps you could re-drill a rotor for 4" bolt pattern, but never read of such.

What scares you about a drum spindle? They are forged, and never heard of one failing. Definitely prefer the 10" drum spindle since beefier and its hub uses larger wheel bearings (SET2 & SET 6). The small bearings in the 9" drum hub can fail (SET 1 & SET4). Indeed, you are better with a drum spindle than the rare disk spindle since most kits bolt to a drum spindle. The SSBC W153 kit bolts to a 10" drum spindle. I wouldn't chose that since it uses the now-rare K-H calipers and rotors. Your best choices to keep your 4" bolt wheels are Scarebird and Wilwood. Scarebird is only ~$120 for brackets and you can source calipers and rotors cheap locally (Toyota & Chevy parts).

The PirateJack kit is just a ‘73+ mopar disk kit. It uses ‘73+ spindles, rotors, calipers, caliper brackets, wheel bearings etc.

The only difference is that the rotors are drilled for the 5x4” bolt pattern, and the outside of the hub registers are turned down slightly so they’re smaller than the original 73+ hubs. It is important to note, however, that they are still a larger diameter than the SBP drum brake hub registers so original SBP drum rims won’t fit.

The only part of the PirateJack kit that isn’t an exact reproduction of ‘73+ original BBP disk brake parts is the finished rotor itself.

The things to consider with that kit are that it does increase the front track width the exact same amount as a 73+ BBP disk conversion. So if your current wheels can’t be pushed out close to a 1/2” without hitting the fenders you’d need new wheels anyway. And the hub registers are still a larger diameter. They’re smaller than the 73+ hubs, but still larger than SBP drum hubs. So if your wheels hub bores fit tight to SBP drum hubs, they won’t fit the PirateJack kit.

On the plus side, if you do ever decide to go BBP, all you need is an off the shelf 73+ rotor.

DoctorDiff, last I heard, was having rotors made that matched the PirateJack kit. So, you can do the same thing and get much better customer service if you call DoctorDiff.
 
I installed the Pirate Jack kit on my 69 Dart last summer. I generally have no real complaints about them. I will admit I was not a fan of the crush sleeves that they use to mate the stock upper ball joints to the larger spindles. I eventually broke down and made other changes (new UCA's with bigger ball joints). But otherwise the component parts all worked fine. I have no doubt that you can also get the same types of parts from Dr. Diff. It really is just a matter of price shopping in my opinion.
 
I installed the Pirate Jack kit on my 69 Dart last summer. I generally have no real complaints about them. I will admit I was not a fan of the crush sleeves that they use to mate the stock upper ball joints to the larger spindles. I eventually broke down and made other changes (new UCA's with bigger ball joints). But otherwise the component parts all worked fine. I have no doubt that you can also get the same types of parts from Dr. Diff. It really is just a matter of price shopping in my opinion.

The ball joint adaptor sleeves have been around a long time. Not saying they're the BEST option, but DoctorDiff has been selling them for years. They do work for those that can't swing a full brake and UCA conversion at the same time. Obviously it's better to go with large ball joint UCA's in the long run. And I know DoctorDiff has posted here before saying he has SBP rotor options for his kits.

As far as price shopping, make sure you're comparing like to like. DoctorDiff's kits all come with Timken wheel bearings and seals, good quality hoses etc. The PirateJack stuff looks like it comes with the cheapest stuff they can get ahold of. And of course, Cass at DoctorDiff has a long history in the Mopar community and GREAT customer service. Personally I think it's worth some extra money just to know you can call the guy and get help if you have an issue.
 
The ball joint adaptor sleeves have been around a long time. Not saying they're the BEST option, but DoctorDiff has been selling them for years. They do work for those that can't swing a full brake and UCA conversion at the same time. Obviously it's better to go with large ball joint UCA's in the long run. And I know DoctorDiff has posted here before saying he has SBP rotor options for his kits.

As far as price shopping, make sure you're comparing like to like. DoctorDiff's kits all come with Timken wheel bearings and seals, good quality hoses etc. The PirateJack stuff looks like it comes with the cheapest stuff they can get ahold of. And of course, Cass at DoctorDiff has a long history in the Mopar community and GREAT customer service. Personally I think it's worth some extra money just to know you can call the guy and get help if you have an issue.

Gotcha on all points. I understand that Dr. Diff has quality parts. I was just sharing that I have no real concerns with what I got from Pirate Jack. Outside of my saga with the UCA's (that actually came from PST), my only other gripe was the brake lines because I installed the calipers rearward. I ended up tossing out the Pirate Jack lines and ordered the stainless lines for rear mounted calipers from Cass. But on balance, the Pirate Jack kit worked and was not particularly expensive.
 
... rotors are drilled for the 5x4” bolt pattern
... outside of the hub registers are ... a larger diameter than the SBP drum brake hub registers so original SBP drum rims won’t fit.
... if your current wheels can’t be pushed out close to a 1/2” without hitting the fenders you’d need new wheels
So both Pirate Jack and Dr Diff now custom-make rotors for SBP (I wasn't wrong in saying I had not read that. I'm reading it now). Downside is one will have to go thru them or a machine shop every time you need new rotors, which is a wear item.
But, won't satisfy the OP since he wants to keep his existing SBP wheels and sounds like they won't fit over the machined hubs.
Are there specific "drum rims"? I thought SBP wheels fit all 62-72 cars, whether drum or disk brakes.
Also, his existing tires that he wants to keep may rub against the fenders.
If his existing drum spindles and ball joints are in good condition, adding disk brakes to those would be simplest, but he doesn't want drum spindles, so back to square 1.
 
So both Pirate Jack and Dr Diff now custom-make rotors for SBP (I wasn't wrong in saying I had not read that. I'm reading it now). Downside is one will have to go thru them or a machine shop every time you need new rotors, which is a wear item.
But, won't satisfy the OP since he wants to keep his existing SBP wheels and sounds like they won't fit over the machined hubs.
Are there specific "drum rims"? I thought SBP wheels fit all 62-72 cars, whether drum or disk brakes.
Also, his existing tires that he wants to keep may rub against the fenders.
If his existing drum spindles and ball joints are in good condition, adding disk brakes to those would be simplest, but he doesn't want drum spindles, so back to square 1.

Yes, if you use the Pirate Jack or DoctorDiff kits you have 73+ style rotors that are machined and have the 5x4" pattern added, and they either need to be sourced from them or machined locally. Given how little most folks drive these cars, they may never need to replace them. I put 70k miles on the 11.75" rotors on my Challenger, they probably couldn't be turned again at this point but they had no issues going through two sets of pads. And I doubt many on here will put 70k on their cars anytime soon.

There is more than one hub bore diameter for the SBP wheels. I thought it was drum vs. disk, but I could be wrong on that. There are definitely SBP factory wheels out there that will not fit the Pirate Jack or DoctorDiff 73+ rotors machined with the 5x4" pattern even though the hub is turned down from the factory diameter, it's right in the disclaimers from Pirate Jack. There are also ones that apparently fit, otherwise why bother with turning down the hubs?

And yes, the 73+ spindles and rotors do increase the track width. So if you don't have ample clearance with your current sbp wheels/tires then that kit may not work without new wheels. Depends on your wheels and tires, I'm sure some will work and others won't.

Wilwood disks also have a large diameter hub (even larger than the BBP 73+ disk hubs), so, factory SBP wheels are a no go with the Wilwood kit too. They also use 1/2" wheel studs.

Totally agree with the OP on the drum spindle thing, at least with the '67-'72 spindles. The 9" spindles do have failures. They were discontinued by the factory early. The larger wheel bearings on the 73+ spindles are better (both drum and disk). And what's "rare" about the disk spindles? The '73+ disk spindles are reproduced, you can buy them anywhere. None of the drum spindles are reproduced, and how many have been tossed at this point?
 
Yes, if you use the Pirate Jack or DoctorDiff kits you have 73+ style rotors that are machined and have the 5x4" pattern added, and they either need to be sourced from them or machined locally. Given how little most folks drive these cars, they may never need to replace them. I put 70k miles on the 11.75" rotors on my Challenger, they probably couldn't be turned again at this point but they had no issues going through two sets of pads. And I doubt many on here will put 70k on their cars anytime soon.

There is more than one hub bore diameter for the SBP wheels. I thought it was drum vs. disk, but I could be wrong on that. There are definitely SBP factory wheels out there that will not fit the Pirate Jack or DoctorDiff 73+ rotors machined with the 5x4" pattern even though the hub is turned down from the factory diameter, it's right in the disclaimers from Pirate Jack. There are also ones that apparently fit, otherwise why bother with turning down the hubs?

And yes, the 73+ spindles and rotors do increase the track width. So if you don't have ample clearance with your current sbp wheels/tires then that kit may not work without new wheels. Depends on your wheels and tires, I'm sure some will work and others won't.

Wilwood disks also have a large diameter hub (even larger than the BBP 73+ disk hubs), so, factory SBP wheels are a no go with the Wilwood kit too. They also use 1/2" wheel studs.

Totally agree with the OP on the drum spindle thing, at least with the '67-'72 spindles. The 9" spindles do have failures. They were discontinued by the factory early. The larger wheel bearings on the 73+ spindles are better (both drum and disk). And what's "rare" about the disk spindles? The '73+ disk spindles are reproduced, you can buy them anywhere. None of the drum spindles are reproduced, and how many have been tossed at this point?

I AM FOLLOWING ALL THESE POSTS , FROM YOU GUYS THAT KNOW WHAT UR TALKING ABOUT , as I`m going back to the stock k frame w/ no torsion bars , probly this summer , '' IF '' , I dont come up with hemi car Im going to look at next month.
Wondering if I could use the 11'' willwood disc brake set up that is on the mag. force front suspension --------spindle size unknown. ??
 
Hey Ron I did use the Pirate Jack kit on my 66, if you look up my post "ordered my disc brake conversion kit today"
Bob
I tried searching for this post and couldn't find it. Do you have a link or point me in the right direction. Thanks
 
If you can not use your OM SB wheels why would you want their setup, Dr.Diff or whoever!? Guess I miss the point.

I don't understand why anyone would keep SBP. But the SBP Pirate Jack, DoctorDiff and Wilwoods kits may not work with most (if not all) of the factory SBP wheels.

I also recalled another reason why there would be two different hub bore diameters for the SBP wheels. The 73+ 10" drum brakes were SBP, but had larger wheel bearings. So they would have needed a larger hub than the earlier SBP drums had.

I happened to have SBP 14X5.5 Rallye Wheels on my 66 and they fit fine.
Bob

Sure, but are your SBP 14x5.5" Rallye wheels factory? The aftermarket reproductions also have different diameter hub bores.

Since you have the Pirate Jack kit, what is the actual hub diameter on the modified '73+ rotors? Posting that would make it easy for people to check their own wheels and know for sure.
 
-
Back
Top