Are they cast iron manifolds or are they stainless manifolds? I have a set from the 86 345 that I dismantled that appear to be stainless but shaped like a cast iron manifold. I believe one or both had diverter valves. I never really looked that close at them.
If you're interested and would like pictures I can snap a few and post them.
Air forums # 1674
1974 20' Argosy Motor Home
1974 31' Excella trailer (parting out, as of 4/1/2015 I have wheels, brake drums, windows & holding tanks left to sell)