800 electrical problems

[Jon Wangelin <jwangelin@domain.elided>]

Greetings IHers

This afternoon I was using my 196 800 (most everything stock) to jump a
dead battery on an '80 turbo diesel.  While the cables were hooked up I
noticed that the amp gauge was pegged out on high.  It took awhile but
the diesel got going.  I unhooked the cables to let the 800 recharge
itself.  Soon I returned to find the 800 not running.  All I could hear
was the electric fuel pump which switches on whenever the key is in the
on position.  I pulled the key and I could still hear it running.  I
poped the hood and saw the ignition resistance wire was fried along with
the positive coil wire.  What are the chances I blew something else?
How many OHM's are supposed to be running through the ignition
resistance wire (12-20)?  My wiring corresponds with an early 800, the
late 800 has a specific OHM's going through it.  Is there a way to check
this?  Should I consider an inline fuse in the future?

Thanks in advance
Jon
PS  Do powerlock differentials come in specific case sizes? ex.
2.72=>3.72 and 3.92=>4.88?