I'm not 100% sure Nash, but I remember the cap being machined as well....it's been a couple years since I installed it. After I broke it it, I run Red Line 75W-90 in it...there was some chatter with the 1st oil fill (Ford dino + modifier), but that has pretty much went away with the Red Line. The only time I ever hear anything is when I do a full deflection turn and that is minor. I chalk it up to the extra friction plates.
You are right about the 2 way...the understeer in a decel turn can get out of hand pretty quick. If it's wet/snow you can find yourself wrapped around a tree in a heartbeat.