Yep, reason for the straight cut was to eliminate the thrust to the back of the case, it was preventing lubrication to the rear case thrust washer and wiping it out, it was later remedied by replacing the thrust washer and plate with a TH350 pump bearing and is standard now in any rebuild, there's arguments on the strength of the straight and helical gears too, some say they're stronger but they have less gear contact than the helical, and it's common to put 1200-1400hp to them with helical gears, soooo???