Furnace Age

Can anyone tell me the age of this Trane Unit - Serial Number:H011870M03? I have looked on buildingcenter.org but unable to make a good determination. Thanks for your help.

Charles Rafford 070.jpg

Looks like 1993. H=1993

Preston’s guide lists this model as manufactured in 1981 and 1982

William - I stand corrected. 81 - 82 it is.