Thanks, Stu!
Yeah, I don't know what those differences might be, myself. I found one from a K3 engine and painted it last night, will see how it looks tonight after work.
It's already got a K7 cam chain tensioner, as that was missing, too. Both of these parts aren't real visible when the engine is installed, so it's becoming a sort of resto-fixup engine? The surface finish on the later parts is, of course, nice and smooth, made in regular molds. It's been about 10 years, I think, since I did the last sandcast - I don't remember, other than the surface finish, how these parts differed. I do remember they seemed crude compared to the K4 and later engines, by far, when the parts were all being hot-molded instead of cast. Heck, today they barely even heat up the molds: they just apply several tens of thousands of PSI of pressure to force the alloy into a mold, water-cool it for a few seconds, and pop it out.