and the pinion gears seem to also have the same length, so it seems like the rear pinion wouldn't have any trouble being used in the front 3rd member housing. ron mentioned there's the possiblity that the reason the front and rear pinion flanges had different part numbers might be because they have threads cut into them to thread onto the end of the pinion. if this is so, you would also have to use therear pinion flange in front and this also creates the possibility that it could spin off if the pinion nut ever got loose, due to the direction difference in the forward riveshaft rotation. but since they don't get loose when in reverse, when in the rear, it probably isn't as big an issue as i'm making it. the only other difference is the area in the cast 3rd member housing for the pinion gear head seems to be larger in the rear 3rd member housing than the front one, to allow for the larger gear head on the rear pinion. this may not be a problem either as the front one still looks like it has plenty of room.

if the 7.5" gear fits the front housing, i have to wonder why it wasn't used. it would have been a HELLofalot cheaper to have one size and cut of gear made than two that don't fit each other, but fit in the same housings. if Kia had done this, it would have made all this work we are doing now unnecessary. it would have made the aftermarket twice as easy and there'd never likely be a question about the strength of the front differential. but then the CV's, if they aren't already would be the definite weak point.