Been working on the oiling system. Replaced the main seal for good measure. Decided to install a new HV oil pump and a windage tray. I did the windage tray on the recommendation of a few people and I know that the later model 454 and 350 motors had them from the factory. Pretty safe to figure the factory isn't going to put something on the motor that isn't useful considering they do everything they can to shave extra expenses.
The tray came from Milodon and I had to get their stud kit to install it. The directions tell you to bottom top the 4 main bolt holes to ensure the stud threads in far enough.
That made me a little nervous to do. I put grease in the tap to collect any metal. It really didn't do much threading. I gave it what I could a couple of times with as much force as I was comfortable with. Didn't want a broken tap in the motor.

The studs threaded in far enough for there to be no unthreaded portion of the stud showing.
I had been wondering what the 2 dimples in the oil pan were for:
There were to clear the windage tray studs. Only they didn't.

Did some research on the interwebs and found several instances of similar problems; even a couple of magazine articles covered it. A few people cut threads off the part that threads into the block; I didn't like this idea and since I didn't have any of the un-threaded stud showing I felt this was unnecessary. So I cut about 3/8" off the top of the studs for the windage tray.
I threaded 2 nuts and washer on the studs before cutting. This was to make sure I had enough stud left to mount the tray. Also running the nuts back off the stud makes sure the threads are good. Now they clear the pan.
The other problem I found with the windage tray is the hole for the oil pump bolt didn't line up. I had to drill it out a couple sizes with the step-bit.
Some of the research I read on the windage tray said people had to notch the tray to clear the oil pump pickup but I didn't have this problem. It was a bit of a puzzle to get the tray on the studs because I replaced the oil pump bolt with a stud.
You can see it is close to the pickup tube collar.
I forgot to mention, before mounting the oil pickup I used straight edges to check for oil pan clear. I have about 1/4" without the oil pan gasket. Once the pump with pickup was installed I put a big gob of grease on the pickup to make sure the clearance I measured was correct. The grease just barely touched the pan without the gasket so I'm good. From off the top of my head most recommend at least 1/4", maximum 1/2". This ensures the pickup isn't hitting the pan and also that it will be fully submerged in oil.
I used blue loctite on the windage tray and oil pump stud nuts. Where the stud threads into the main cap, I used red loctite. I also used the 609 loctite on the oil pump pickup that presses into the pump. You can also see the Milodon pickup as a bracket that uses one of the pump cover bolts.