Might be nothing but I am seeing L46 on stickers that are on the engine and I dont know if I should be concerned since what I ordered in the part description says "Replacement L31 engine with an engine code R. This engine has no mechanical fuel pump provision."
The part number 12681432 is what I ordered here which says "not available" nowdays.
https://www.summitracing.com/parts/NAL-12681432
I contacted Summit and asked and they said that Chevrolet Performance will have to answer why the L46 vs L31. So tomorrow Ill hear what they can tell me. Maybe its no big deal and its still the vortec head L31 and the stickers say L46 for some other reason. Im bummed cause I nearly have it installed today when I saw this as I was raising it out of the crate to mount up.