Original 1968 Factory 340 Equipped With Hot Air Stove?

Treblig said
According to "Yearone" the same one was use from 68-71

Mopar Perf P2946105 LH exhaust manifold
Click to expand...
All that P2946105 does is keep the plug wires from burning up. I can't recall any 340s before '70-'71 having the hot air system that the OP mentions