I tried to fix transmission cracks on a Ford HD Industrial. Failed miserably. One crack was 15-18" long and others were 3-9" long. Everytime I heated it up (pre-heat), I found more cracks. It also sounded like rice crispies when it was cooling down. That was with both Ni rod and some supposed miracle Cast Iron repair rod. Only miracle was that I parted with my hard earned bucks!
I had a couple quotes on getting it done right. That means stripping the case down to bare, washing it and degreasing it then taking it to a cast iron repair expert. They wanted 150 bucks per crack. They would heat it in an oven and weld it in the oven at some high temp (850-900F strikes a cord, but that isn't for sure!). Then they would do a 48 hour thermal cycle to completely stress relieve it. As I had several large and many small cracks, I didn't go that way.
I was lucky in that I found a good case for $75 and transfered the guts to it.
If you are going to have more than $2-400 in the weld repair, you may be better off getting a good case. For about 40-50 bucks you can get some magnaflux crack penetrant dye. The kit comes with 3 parts. Cleaner, dye and a white to help show the cracks. There may be more cracks than you think. (Was for me anyway).
"Pictures", what pictures?
jb