King and Link Pin to ball joints and modern brakes

[SWFL]

I assume the parts will just bolt up to a '77 and older 2WD/RWD frame. 

 

1) Ball joint spindles either OEM or HB drop spindles. Will 720 spindles work? HB or Pathfinder?

 

2) Control Arms any different? Will later ( 720, HB, Pathfinder ) ones fit?

 

3) Hubs if going with better brakes. 720 only or will HB & Pathfinder ones fit?

 

4) Calipers and rotors. I know there's a lot of options for that.

 

5) 15" wheels if going with 11" brakes.

 

6) Misc like; lines, hoses, valves and M/C. 

[wayno]

If you have a kingpin front end you cannot just mount ball joint front-end parts on and have it work, the geometry is different, it can be done as I have done it to my 521 work truck, but it took time for me to get it right.

 

After I did it I would never have suggested that anyone do it the way I did it, I had upper control arm bolts breaking, but eventually I figured everything out, but you have to know how to weld to make the upper control arms around 3/4" longer or cut around 3/4" out of the lower control arms, making upper arms is easier, you also have to mount the right arm on the left side and the left arm on the right side to get the castor where it needs to be, it is complicated, I did it back before Ratsun came into being, I also added power steering, if adding power steering the frame needs to be beefed up in the steering gear area.

 

I also do not know how much different the 620 kingpin frame is compared to the 521 kingpin frame, I know a few things are different.

[datzenmike]

wayno's right if it were easy everyone would have do it.

[SWFL]

So the frame mounting points are in different locations?

 

Are all '77s king and link, or was there a mid year change?

[datzenmike]

'72.5-'77 are king pin.

 

Build dates are in the driver's door jam and the model year starts the previous year's summer or fall.

 

The '77 model year truck starts August '76 and ends July '77.

 

Chassis or car numbers for the '77 King Cab fall between 156,752 and 260,000. Car numbers are on the engine tag mounted on the left inner fender near the coil.

 

 

[SWFL]

Are new bushings and whatever other wear items still available? 

[Wildcat Walker]

 

[Wildcat Walker]

https://i.postimg.cc/4N48fY1r/received-1332407467550416.jpg

[SWFL]

1 hour ago, Wildcat Walker said:

https://i.postimg.cc/4N48fY1r/received-1332407467550416.jpg

 

How much?

[iceman510]

Interested too.  Have a '77 620 to convert.

[ducky]

lol and i want a set too for my 76!

[wayno]

If it were easy to do and cheap enough Mike K would have figured out a way, but it is not easy or cheap to do unless you do it yourself, welding is involved, parts from the late 620 and 720 are needed, to do it right late 620 lower control arm bushings need to be installed although one can use washers to take up the slop if using the existing bushings, the upper control arm mount bolt holes should be drilled out and threaded for 720 upper control arm mount bolts.

 

I upgraded to the V6 hardbody rotors/dual piston calipers using the late 620 lower control arms and tension rods, I used 2 sets of 720 upper control arms to make a set of upper control arms that were 5/8" longer, I put the extended left upper control arm on the right side and the extended right upper control arm on the left side to get the castor where it needed to be, when I took it to the alignment shop they said I had it within 2 degrees on everything, but it needed new tension rod bushings, I found a set of new bushings and made them shorter for the front and longer for the back as the 620 tension rods were slightly longer, I drove it that way for years after I figured everything out, but the power steering I added a while later destroyed the frame horn, I had to repair it several times.

 

I use 14" 620 disc brake rims on all my trucks, I can use stock 520/521 14" rims if I hammer the high spots down on the inside of the rims, I now use the 1986 disc brakes on everything, there was not that big of a difference between the single piston verses the dual piston caliper to justify the extra expense, and I haul large heavy loads of firewood, by the way my 521 has been a dually for couple decades.

 

I have hauled way heavier loads than this.

 

It is also a dump truck now, this truck rolls over the scales at 3900lbs, it needed great brakes.

[thisismatt]

The other day a guy on FB from Mexico posted about using some isuzu TFR pickup upper arms that supposedly bolted right in, with 720 lowers.  He hadn't gotten it aligned, but showed some pics and it looked decent.

[Wildcat Walker]

No parts from late 620 are required. 

 

- 2WD D21 Lower control arms, heavily modified

- 2WD 720 UCA Cross Shafts and bushings

- Custom UCA's

- D21 upper and lower ball joints and spindle/hub assembly

- Z32 (with custom rotor adapter) or D21/WD21 brakes

 

I could make these, but it wouldn't be cheap. It's not impossible or hugely difficult, but very time consuming. 

 

- 

 

 

 

[thisismatt]

3 hours ago, Wildcat Walker said:

No parts from late 620 are required. 

 

- 2WD D21 Lower control arms, heavily modified

- 2WD 720 UCA Cross Shafts and bushings

- Custom UCA's

- D21 upper and lower ball joints and spindle/hub assembly

- Z32 (with custom rotor adapter) or D21/WD21 brakes

 

I could make these, but it wouldn't be cheap. It's not impossible or hugely difficult, but very time consuming. 

 

- 

 

 

 

Everybody wants them until it's time for...💵

[ducky]

9 hours ago, Wildcat Walker said:

No parts from late 620 are required. 

 

- 2WD D21 Lower control arms, heavily modified

- 2WD 720 UCA Cross Shafts and bushings

- Custom UCA's

- D21 upper and lower ball joints and spindle/hub assembly

- Z32 (with custom rotor adapter) or D21/WD21 brakes

 

I could make these, but it wouldn't be cheap. It's not impossible or hugely difficult, but very time consuming. 

 

- 

 

 

 

 

i'll gladly pay to update my brakes without giving money to some chinese made garbage. put a figure and a general timeframe here or in pm's and i'll let you know if it's something i can swing. if not soon, then in the future. because the time will come when my king pins go bad, if they aren't a bit bad already. the four wheel drum brakes work fine, but im one panic stop away from losing my truck

[SWFL]

Just curious, why wouldn't it be easier to weld ball joint mounting brackets in the correct location on the frame, or section in that part of the frame from a ball joint frame? Seems like a lot less work and trouble than engineering hybrid control arms.

[thisismatt]

Most people want a bolt-in solution that doesn't require pulling the engine, steering, etc

[Moist Lightning]

I was thinking of looking for universal adjustable uppers that have the correct geometry(uppers might need custom cross shaft to be bolt in) and weld new lower mounts to get some lower control arms is the correct position, will take a bit of research to find the correct combo of parts but I think it should be doable (probably need to weld new mounts for some different tension rods for the lowers too). Anyone have thoughts on this?

[Wildcat Walker]

5 hours ago, Moist Lightning said:

I was thinking of looking for universal adjustable uppers that have the correct geometry(uppers might need custom cross shaft to be bolt in) and weld new lower mounts to get some lower control arms is the correct position, will take a bit of research to find the correct combo of parts but I think it should be doable (probably need to weld new mounts for some different tension rods for the lowers too). Anyone have thoughts on this?

No. There is nothing available off the shelf in a universal/ adjustable configuration that is small enough to be used for 620 UCA's.

The lowers are even more unique. Again, as has been stated, you're not going to be able to just buy something and bolt it on. There is a reason, those of us who have done this swap, have gone to great expense to do so. If you want to custom design and eningeer a solution on your own, you are free to do so. 

 

Sorry to bust your bubble. 

[Moist Lightning]

19 hours ago, Wildcat Walker said:

No. There is nothing available off the shelf in a universal/ adjustable configuration that is small enough to be used for 620 UCA's.

The lowers are even more unique. Again, as has been stated, you're not going to be able to just buy something and bolt it on. There is a reason, those of us who have done this swap, have gone to great expense to do so. If you want to custom design and eningeer a solution on your own, you are free to do so. 

 

Sorry to bust your bubble. 

I appreciate the feedback and you could very well be right , I haven't really done any research yet its just an idea thats been kicking around in the back of my head but im not completely convinced yet. 
adjustable uppers are basically a ball joint mount, threaded rod, threaded tube, heim joint and cross shaft. Can probably find a universal from sumit and shorten it for cheaper than making one. Might need a custom cross shaft though. and if welding new mounts for the lowers i feel like there is something out there, probably not something from a modern commuter vehicle, more likely something aftermarket for another old car or niche motorsport (for example I was looking at circle track steering racks for power steering as the are very narrow). If I find something in the future ill update

Edited March 20 by Moist Lightning

[Wildcat Walker]

2 hours ago, Moist Lightning said:

I appreciate the feedback and you could very well be right , I haven't really done any research yet its just an idea thats been kicking around in the back of my head but im not completely convinced yet. 
adjustable uppers are basically a ball joint mount, threaded rod, threaded tube, heim joint and cross shaft. Can probably find a universal from sumit and shorten it for cheaper than making one. Might need a custom cross shaft though. and if welding new mounts for the lowers i feel like there is something out there, probably not something from a modern commuter vehicle, more likely something aftermarket for another old car or niche motorsport (for example I was looking at circle track steering racks for power steering as the are very narrow). If I find something in the future ill update

Any off the shelf parts will require modifications similar to that involved with building a custom part, in some cases more involved. I have a pile of SPC UCA parts for sale. New never used. They came from Summit, I'll make you a good deal. 😁

[wayno]

In my opinion getting 2 sets of 2wd 720 upper control arms and cutting them in such a way as to be able to have them 3/4" longer when welded together is the easiest/cheapest solution, they are just bolted in position, put the left arm on right and the right arm on left, this puts the castor where it needs to be.

 

If you want to lower the truck or it is low already you put the right UCA on upside down right on the right side, left on left side upside down, this stops the control arm ball joint from binding, a little grinding is needed so that the ball joint sits flush on the arm, I did this to my 1966 Datsun 520 and it was 6" lower than stock in the front.

 

[Moist Lightning]

It not so much the work involved but the type of work. Watching bluehands videos on chopping and welding the lowers makes that type of modification seem out my capabilities. modifying adjustables / hiring someone to weld mounts to frame for lower is just what would be easiest for me(also have a cheap machine shop if i need parts machined). Honestly if someone started making a nice set again I would buy. Have a set of bluehands but i got 2 trucks so have to figure out something for the second eventually. Not in a rush to get it done but if i make any progress ill make a post. Otherwise I'm hoping someone starts production in the meantime. Additionally it seems everyone who has made them in the past either has to charge a lot (understandable) and / or cant produce many. so any part of the modification that we could find prefabbed parts to use would probably help, even if a lot has to be custom still. Like you said could just be a pipe dream though.

[Moist Lightning]

On 3/17/2023 at 9:10 PM, thisismatt said:

The other day a guy on FB from Mexico posted about using some isuzu TFR pickup upper arms that supposedly bolted right in, with 720 lowers.  He hadn't gotten it aligned, but showed some pics and it looked decent.

 

 

Only dimensions I could find so far
 

Control Arm Maximum Length	237
Control Arm Maximum Width	288.5

 

Mounting Hole Diameter

12.3

 

 

Someone in the usa should try to order one, I would but shipping is too much outside usa for what ive found so far

https://www.ebay.com/itm/125348119710 

Edited Wednesday at 03:35 AM by Moist Lightning