I use a Moroso 21604 pan on my BBC which is very similar to the 20370 that is popular on a lot of SS big block Chevy's .
I have two versions of this pan ,one with the diamond screen and an earlier one with a louvered tray.......On the same engine with no other changes the louvered tray pan is good for a solid .070 ET and over 1 mph more. This was realized when I took the louvered pan off my spare engine at a race to replace the damaged pan on my engine in the car.
Ishihara -Johnson
http://www.crank-scrapers.com/ is the company in Florida that manufacturers scrapers and trays for just about any engine....I found quite a bit of HP on my AMC Stocker using their stuff.