Lsd Questions!

[95 red 240]

ok i have a 95 base model 240( 4 lug, auto) found a lsd diff. from a 95 se 1. will it bolt up right ? 2.will i have to change flanges( i thought all s14 flanges were same didn't have to change them but wanted to make sure) 3. How can you check to make sure it is good condition( like i have heard of people looking inside but what do you check for/look for the yard is pretty repitable but would just like to check and make sure)

Thanks for all your help!:D