That is the 3/4 windage tray which is good. There is a full length tray also. The 326,350, and 400 all used the same 3.75" stroke and 3" main bearing size. Only the bore changed. So the cranks interchange. The 421, 428, and 455 used the 3.25" main bearings so that is different. Did you clean that yet? Because if not, that is super nice condition! I see the 350 cast clearly on the side. Pretty nice of them to do that, eh?
