What year 22r motors will fit my 1981 toyota pickup 4x4 4speed tranny?

i have a 1981 toyota pickup, i need a motor and i am wondering what other year model 22r motors will bolt right up in it and to my 4 speed transmission? Please Help!!!What year 22r motors will fit my 1981 toyota pickup 4x4 4speed tranny?Any year will fit, but stick with earlier models (pre-1986) if emissions is an issue in your area