1998 ford f150 4x4 what transmission do i have , also what should the tag on the back end of the transmission read mine reads F85AA as far as i can see is this the right number i am looking for when looking for a replacrment tranny????

 

i went under and took the tag off and it reads F85A-AA what type is this the mechanic here sez it reads like a 6 cylinder but it is 8 , he sez it should end in CA or HA ??is there a difference in U.S and CANADIAN numbers ??also tag on the door sez U type .