I just installed my new 2056 motor on Thursday . No, I haven't even fired it up yet....hopefully Monday. So after installing 2.0 exchangers and 2.0 Bursch, I started plumbing in my heat ducting. I have it 90% together (with exception of connecting flappers to long tubes), and I am missing some parts.

Does anyone have these parts they will sell me?

NLA for a long time. don't forget the "branch gaskets" (reference Dr. 914)

Johnnie. I have these parts. I'll send a pm with all the info. Bill

Brad Mayer told me he leaves the flappers off. If they ever get stuck, you've got no heat.

I believe the flaps only function as "check valves" at low engine speed when the heater blower motor is on, preventing cavitation as the electric fan blows back into the engine cooling fan. As engine speed increases the engine fan overcomes the pressure of the electric fan, opens the flaps, and provides most of the air moved through the heat exchangers for heat and defrosting. My engineering gut feeling is you might have some small decrease in heating/defrosting efficiency if you do not have the flaps and do run the heater fan at engine idle. Of course, I suspect you will have a whole lot less heat at idle if you both run without flaps and without electric blower.

If you leave the flaps off or they get stuck open (#19/20) then using your auxiliary heater fan will blow back into the fan shroud. Not bad, per se, but not really efficient for heating.

The flaps getting stuck closed would leave you with no heat only if you have no aux fan. If you have an aux fan then you probably wouldn't notice.

The aux fan only comes on when you pull the heater lever all the way up. Raising the lever up partially will open the 'valves' and let the hot air be forced in by the engine fan.