What rear is this?

That is an open 9 1/4, with what looks to be high 2, low 3 gear ratio. Quite strong rear end, and gears and lsd's are available, cause there's lots of them in trucks.
It does unfortunately use c-clips to hold the axles in . Not a problem stock, but in a hotrod application i would narrow it to the width i want, and then put 8 3/4-dana 60 /nine inch ford ends on it.