I trust by now most have realized that the 5 speed transmission did not app ear until mid'95 and latter. Every 140 before that had the same transmissio n. To answer the question about the 722.3 and the 722.4 difference- there real ly isn't a great deal of difference when diagnosing a problem. The 722.3 ha s less parts as it is a 3speed for most application I believe. I could be i ncorrect on that but an 80 450 has a 722.3 3speed auto.