weird heater and A. C. firewall hose connectors

[68 Charger Mistress]

Hi all,  I just picked a 68 Charger but it has not one set of heater core lines, but two sets of line hook ups on the fire wall along with a set for factory A.C. just wondering if any of yall might be able to help me to figure this out? Thanks for your help.

[Rolling_Thunder]

should be three heater hoses...    two going to the engine and one "U" shaped hose connecting the temp valve to the heater core

[b5blue]

I just looked at a 68 satellite that had the same thing