When I took apart my doner engine, a 390 from a 67 LTD, it didn't have a valley tray in it. The bottom of the intake manifold had the tin pan type cover that attaches by hammer rivets. The entire insides of the tin pan was a burnt oil crust that looked like a charcoal briquet.
When I reassembled it I used a valley tray, but left the tin pan off. I did this because I closed off the exhaust cross over that makes it get so hot. Hope these pictures help. I would use the valley tray either way, even with my new Edelbrock intake that has no cross over. Dave J
Hm, attachments aren't working?