[Spridgets] front disc brake conversion and differential

[derf]

Just get front brake parts from a donor car.  It shouldn't be too expensive.

Personally I would find a diff from a later car, 3.9 or 3.7.  They
came in late 70s Midgets.  The 3.9s are kinda rare and the 3.7s rarer
still.  I sold a 3.7 on ebay a while back and the guy who bought it
was in Scotland.  He was willing to wait 6-8 weeks for shipping.
You should have a 4.22 stock and it will probably work fine except it
might get annoying at long intervals of 70+ driving as opposed to the
3.9 or 3.7.