Pirate Jacks front disc kit question

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tapping the spindles just sounds janky to me. it also removes the fail safe of having a nut and bolt vs just a bolt that can (maybe) go on walkabout before you know anything is really really wrong.

i'm not saying ma mopar is the be all and end all in the engineering department, but they made millions this way and it doesn't seem to be a problem.

there's work arounds to this situation, and i think drilling and tapping would be about last on the list.
 
Tabs on the lower control arm for sway bar were welded on in a separate process. The welds like all welds of the age were complete garbage. I have several pairs of these control arms and I’ve been fixing some of the welds. The control arms are most likely stock.
Clearance issues come into play in this case because the lower ball joints are completely different. Mounting locations are further apart and the front ball joint mount is lower than the 67-72 A body. If you want to buy additional ball joints they are the 68-72 B-body and 73-76 A body. All the same. Not super expensive.
The best way to fix the issue is to go to the 73-76 swaybar. Seeing as how you are well into rebuilding the front suspension best solution is to change the hardware. Shallow nut and shorter bolt should clear. Just remember that the hardware is the only thing holding the suspension together. Use grade 8
 
AbodyBB said:
The best way to fix the issue is to go to the 73-76 swaybar. Seeing as how you are well into rebuilding the front suspension best solution is to change the hardware. Shallow nut and shorter bolt should clear. Just remember that the hardware is the only thing holding the suspension together. Use grade 8
Click to expand...
swapping to the 73~76 bar would also entail swapping out the K-member and lower control arms (and motor mounts).

short of cutting off the tabs and running an aftermarket bar with different pick up points the most practical way forward would be different nut/bolt set up.
 
Here's a set of 1972 and earlier LCAs positioned to illustrate the position of the sway bar tabs.

Straight edge against outer part of the tab.
DSCN0169.JPG



In the same position, notice how the LCAs aren't parallel, which illustrates the position of the tab.
DSCN0170.JPG



When they are sort of parallel, note how the tabs appear crooked.
DSCN0171.JPG



I guess all this really illustrates is that sometimes it can be hard to visualize a 3D object in two dimensions.
Since when the front-hung, single piston brakes were introduced for 1973 the sway bar tabs were moved inward, I'm guessing avoiding interference was at least one reason for doing so.
I still think the best solution is a shorter bolt and a little thinner nut loctited on. Maybe a little grinding on the tab if it still needs clearance.
 
AbodyBB said:
Tabs on the lower control arm for sway bar were welded on in a separate process. The welds like all welds of the age were complete garbage. I have several pairs of these control arms and I’ve been fixing some of the welds. The control arms are most likely stock.
Clearance issues come into play in this case because the lower ball joints are completely different. Mounting locations are further apart and the front ball joint mount is lower than the 67-72 A body. If you want to buy additional ball joints they are the 68-72 B-body and 73-76 A body. All the same. Not super expensive.
The best way to fix the issue is to go to the 73-76 swaybar. Seeing as how you are well into rebuilding the front suspension best solution is to change the hardware. Shallow nut and shorter bolt should clear. Just remember that the hardware is the only thing holding the suspension together. Use grade 8
Click to expand...

Except there are quite a few people that run the 73+ spindles and brakes on '72 and earlier cars. The usual interference point with the '67-'72 sway bar is the caliper if you try to put the caliper to the front, and that has been covered here many times. The interference at the ball joint is not nearly as common an issue. Yes, the factory welds varied wildly in quality, so it may be that those are factory arms. The pictures from the OP aren't great, but again, it looks like the tabs are in a slightly different position than many of the ones I've seen. It doesn't take much, and I don't think the interference in this case is a major issue. They're 50+ years old, so they may have been tweaked or damaged at some point too.

Using a '73+ sway bar is not at all an option unless you change out the entire K frame and move the tabs. Not at all the best way to fix the issue.

S'cuder said:
Here's a set of 1972 and earlier LCAs positioned to illustrate the position of the sway bar tabs.

Straight edge against outer part of the tab.
View attachment 1716178412


In the same position, notice how the LCAs aren't parallel, which illustrates the position of the tab.
View attachment 1716178416


When they are sort of parallel, note how the tabs appear crooked.
View attachment 1716178417


I guess all this really illustrates is that sometimes it can be hard to visualize a 3D object in two dimensions.
Since when the front-hung, single piston brakes were introduced for 1973 the sway bar tabs were moved inward, I'm guessing avoiding interference was at least one reason for doing so.
I still think the best solution is a shorter bolt and a little thinner nut loctited on. Maybe a little grinding on the tab if it still needs clearance.
Click to expand...

It's definitely hard to tell what's going on with the OP's LCA's based on the supplied pictures, for sure. The factory tabs have a lot of bends/angles and look quite different from different angles.

Nonetheless, the OP isn't anywhere near the only person to have done this swap and that's not the "usual" interference point. The hardware in the OP's picture definitely looks like part of the issue, the bolt is too long (it's a standard grade 8) and the nut on the back is very thick. And I don't think he's losing a ton of motion, so a slightly shorter bolt/thinner nut would probably be more than enough.

DoctorDiff sells these bolts with a different style nut, and if I remember correctly the "standard" grade 8 size you'd be able to get at the hardware store is too long, I think he orders a length that's an 1/8" or 1/4" shorter than the typical hardware store selection

Mopar A/B/E Body 5/8" Lower Ball Joint Bolts and Nuts
 
72bluNblu said:
Except there are quite a few people that run the 73+ spindles and brakes on '72 and earlier cars. The usual interference point with the '67-'72 sway bar is the caliper if you try to put the caliper to the front, and that has been covered here many times. The interference at the ball joint is not nearly as common an issue. Yes, the factory welds varied wildly in quality, so it may be that those are factory arms. The pictures from the OP aren't great, but again, it looks like the tabs are in a slightly different position than many of the ones I've seen. It doesn't take much, and I don't think the interference in this case is a major issue. They're 50+ years old, so they may have been tweaked or damaged at some point too.

Using a '73+ sway bar is not at all an option unless you change out the entire K frame and move the tabs. Not at all the best way to fix the issue.



It's definitely hard to tell what's going on with the OP's LCA's based on the supplied pictures, for sure. The factory tabs have a lot of bends/angles and look quite different from different angles.

Nonetheless, the OP isn't anywhere near the only person to have done this swap and that's not the "usual" interference point. The hardware in the OP's picture definitely looks like part of the issue, the bolt is too long (it's a standard grade 8) and the nut on the back is very thick. And I don't think he's losing a ton of motion, so a slightly shorter bolt/thinner nut would probably be more than enough.

DoctorDiff sells these bolts with a different style nut, and if I remember correctly the "standard" grade 8 size you'd be able to get at the hardware store is too long, I think he orders a length that's an 1/8" or 1/4" shorter than the typical hardware store selection

Mopar A/B/E Body 5/8" Lower Ball Joint Bolts and Nuts
Click to expand...
I ordered bolts. Hopefully it works. Thanks.
 
72bluNblu said:
I mean, if you guys really wanna do something that shouldn't be necessary for the swap rather than figure out the actual problem, sure, tap the ball joints.

But again, that shouldn't be something you need to do. It looks to me like the sway bar tabs themselves are the issue, whether they were added or need repair, something appears to be "off" with their placement.
Click to expand...
When I did my conversion, I used the original control arms and lower bushings. I just had to drill out the lower bushings to adapt to the K & H disc brake spindles. I used all the stock hardware. Been working fine for years. The 69 Dart did have stock 4-wheel power 10" drums to start with and I even used the same M/S and no PP valve (I do not drive it in the rain, so no spin-out). See car in photo.
 
Swinger 340 said:
When I did my conversion, I used the original control arms and lower bushings. I just had to drill out the lower bushings to adapt to the K & H disc brake spindles. I used all the stock hardware. Been working fine for years. The 69 Dart did have stock 4-wheel power 10" drums to start with and I even used the same M/S and no PP valve (I do not drive it in the rain, so no spin-out). See car in photo.
Click to expand...

Drilling out the lower ball joint only works going from 10” lower ball joints to the KH spindles. Since this is a 73+ disk spindle swap what’s necessary for a KH swap really isn’t relevant.
 
Here's some more pics. I hope they help. Maybe I'm overthinking this. I just wanna be sure, when I hit that curve, I make it around it lol.

20231218_160125.jpg


20231218_160130.jpg


20231218_160155.jpg


20231218_160216.jpg
 
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