When I did this a few weeks ago I used the oil pan off of the 350 but did not move the windage tray. I kinda wish I had used the original pan off of the 300 just for the added capacity. I did not see any difference in the operation of the engine without the windage tray. Also, I'm not sure if the crank bearing caps from the 300 have the holes for the windage tray fasteners. Blue locktite should be fine on anything you bolt together in there. Make sure you torque to spec.

I think it would be an interesting experiment to try running the lighter flywheel. With that said unless if you have access to an engine dyno it would make it alot easier to try it.

__________________
Jim