521 Ball Joint Mod

[Juanjoze]

It's fine too many shims, or it's better (safety) cut a bit the upper control arm.?

 

 

[bilzbobaggins]

That battery name. lulz

 

Hell of a job on the ball joint swap.

[]2eDeYe]

The stock 620 suspension has 8mm or so spacers there and they do make the shims just for this reason. 
I would say they are fine as long as you have full thread engagement on the bolts thru the frame. 
 

Nice work on documenting the swap. Thank your friend for figuring it out. 

[Stoffregen Motorsports]

If you don't like using the shims, maybe machine some spacers out of steel and use those instead.

 

Back to the wheel thing - I think what's different is the aluminum slot mags. They appear to have a smaller center bore. So saying 14" wheels don't fit isn't wholly accurate. Stock 14" wheels will fit, but not those slot mags.

[Juanjoze]

I had taken some good information from here, as mentioned above it will be why I use the newer hubs with a vented disc.

 

http://www.bluehandsinc.com/hub-info.html

 

Hub Info

The best hubs are from the 10/82 - 11/85 Datsun 720 2wd pickup.  They allow the small center hole rims to be used.  The 620 disc hubs and pre-10/82 720 hubs will also work without modification(they are the same hub).  If you cannot find a '84ish 720 for the parts, you can mix and match parts a bit.  The correct Hardbody(D21) rotor will bolt to the back of the 620 and 720 hubs.  On the 620 and early 720, the hub is the only part you can use. The rotors and calipers will not work.  On the late 720 and HB, you can use the hub with large center hole rims, or the hubs can be machined to fit the smaller center bore on the older rims. 

[NC85ST]

With the wheels, it makes me wonder if there was a difference between the Mexico trucks and the US version. The mags clearly worked on the truck before but not now. The reason I bring this up is because back around 1984, I bought a brand new set of aluminum wheels for my ‘70 521 and I have those same wheels on my ‘85 720 now.