I still think one grill is sufficient with our T1 motors. The problem is the restriction created by the "rain shield" underneath the grill. Terry did a clever thing there. He sort of keeps the "rain shield" benefit by using the louvers and still allows more air into the engine compartment. Very good Terry ! I have looked under a two grill engine lid. There is a substantial difference in the design of the "rain shield". It allows more air in than a one grille design does. If one wants to add another grill it would be imperative to redesign a different and bigger "rain shield" underneath as well.
I don't know if I ever mentioned this before but that hole in the firewall in front of the engine fan on my VS is covered up with my stainless steel firewall dress-up. The only air the engine gets is thru the grille in the deck lid.
I'm wondering if through all the years the mold for the "rain shield" part has been used an/or re-made if it's changed or shrunk. Or the mold flashing is trimmed differently by different workers. This would cause this component to be drastically different that an original....Hmmmm.................Bruce