I installed the 2 qt size about 3 months ago. Use it for pre-oiling as you have indicated. But I would strongly recomend you to get the electric valve. Depending were you put the valve, you may get tired of opening the hood, starting (and as most of these monsters do, stall a couple of times) and closing the hood.
I went with the 2QT because of room restrictions, but if you've got space, go for the 3QT.
By the way, if you happen to have a mechanical
oil preassure gauge in your dash, it's a great feeling to see that gauge load up to 40PSI or more and slowly decrease befor start-up. Now you know it's ready to play
Hector