The solid sheet-metal tray, as found in some stock pans, controls oil sloshing forward & back from climbing up and getting caught in the crank, etc. but has a few flaws for high performance use.
It interferes with drain from the walls, since the oil has to "find" the open area by running across the tray surface, and the droplets tend to bounce back up from a solid surface and strike the crank.
A solid tray can be improved by punching (not drilling) 3/8" holes through from the top using a gasket punch and a 3 lb. hammer with a block of wood as a back-stop. This makes a slight funnel in the upper surface to promote drainage, and a small lip underneath to prevent oil from passing through the wrong way. Yes, you'll have to re-sharpen it a few times, I heat-treat mine with Kasenite.
A tray should always point down from the pan rail, not only to promote drainage but to prevent oil from splashing up. The area at the ends should be solid (no holes) for about 1" wide to block as much splash as possible.
Vertical baffles are annoying to attach, since the pan rail doesn't help much here, but they can also limit front to rear wave motion and keep oil close to the pick-up head. The height of the baffle should be slightly above the normal oil level, the width matches the pan, but the entire height isn't solid - there should be a generous hole pattern near the bottom to allow oil to flow back to the pick-up head at all times. The total hole area should be at least twice that the pick-up head. An obvious shape is a simple vertical cylinder at least 2" larger OD than the pick-up head, vented all around with big holes near the bottom; the side is slotted to install the pick-up tube. I've seen what looked like a coffee can used - the bottom was riveted to the pan bottom, then soldered for sealing. Vizard suggests that simple 10-32 nuts and bolts are fine if soldered in place.
Remember that all shapes must clear the pick-up tube, discharge tube, pump body (enough to permit installation), and the entire rank counterweight path.
