early ford juice brake question

I just have a quick question...I did a search the other day and didn't see an answer, although I'm sure it's been covered alot before.

I have a set of square back spindles. Will some early juice brakes that came of a rod with round back spindles directly fit my square back ones, with no mods?

thanks

 

I am pretty sure the squarebacks have diffrent bolt hole spacing,than the later model round-backs. The kingpins are the same diameter though. Anyone else?? Sparky

 

Up to 36 the spindles had round on top/bottom and flat sides. Then 37-41 was all round. Then 42-48 was all square.

The early up-to-36's had a smaller backing plate bolt pattern, but you could file the later backing plate holes to match. Then you'd need an adapter kit which consisted of spacers to put the juice brakes on.

 

It looks like the backing plates will bolt up fine.