I have a BQ combo kit and want a thermosatic element that works for a 507 cooler. Acording to our supplier, he says go with the kt-43-sc. This, according to the sporlan bulletin, is not right and should be a kt-43-pc. He swears that others are using the sc charge. It looks to me light the freezer element sz is good for 404 and 507, but the sc cooler element is only good for 404a. Any thoughts?