626 Differential? Will it fit?

hey there, Got a 1982 B1800, Just wondering if anyone knows if the dif out of a similar year Mazda 626 (82-83) would fit straight in?

i've got smaller wheels/tyres than original, and that dif ratio should solve my problems, so i'd preferably like to find one that will bolt up!

Cheers guys really appreciate any answers!