Overspray on the bellhousing would be a good way to tell the original color, if it has overspray there. I've read that '66 Suburbans with 327's had blue engines, and have seen a couple pictures of different blue valve cover. But it was blue, not teal.
327green:
Suburban 327 blue:
http://67-72chevytrucks.com/vboard/s...d.php?t=525379
