i am going to change all my fluids but i'm not sure which t-case i have. i know it's a 241 but not sure if it's standard or HD. the sticker under the hood says standard but there is a pto attachment point on the tranny. does that make sense? it is a 97 4x4 with tow package (i think)

also, is there any particular brand of ATF that will work best with this?

 

the hd has a one piece tail housing and the light duty has a 2 piece tail housing