I believe there was also a shorter stock one. Maybe that is what the repop one is supposed to be. There shouldn't be much oil splashing around at the front of the motor since the oil pan is so close. I don't think the windage tray is a real critical part. Like you said, the later motors just have the welded in baffle covering the deep part of the pan and left out the windage trays. This was supposedly to keep oil from splashing onto the crank and adding drag at high RPM's Maybe the experts can chime in and provide opinions on how well they worked.