Heil - Intl Comfort

Does anyone know how Heil /Intl Comfort code their units?
M# NFCX3600C2. S# L0127.
M# FSM242400A1. S# A0610.

Lennox M# CB427UH-024.
Thanks
Charlie

My best guess would be that the top one is a 3 ton manufactured in 2001 and the bottom one is a 2 ton mauufactured in 2006

http://hisearch.web.officelive.com/Heil.aspx
http://hisearch.web.officelive.com/Internationalcomfortproducts.aspx