Trane used alpha codes in their serial numbers to determine year of manufacture. They started this in 1987 with the letter B and skipped the letters I, O, Q, U, Z
In 2002 they started their serial numbers with the year it was built.
The first letter of the serial number gives the year of manufacture as follows:
Thanks a bunch for your help. I had a stinkin suspicion that were 88 but did not want to guess. Thanks for the Trane info. Will save it for later. Take care.