Call them and ask their recommendation but pretty sure it was the Mini GenIII universal. Has a/c, heat and defrost. Everything bolted up well on my straight 6 250, with only a little grinding. Not a fan of their tensioning mechanism, but it works. Blower and evap unit fit in your cab, keeping the engine bay looking relatively stock.

'69 1/2T stepside, Sea Foam Green, 250 L6 w/ 3 on the tree, not an option on it, in the family since new.