My question is one tcase stronger than the other?
Practically, no. But if you want me to get technical, the forward shifting t/case (assuming its a post-1984.5) has what we call a "Quiet-Run" gear design. It has an input gear that is slightly weaker then the non Quiet-Run gear sets, but, the cluster gear is then wider on the Quiet-Run gear set making it stronger than the non Quiet-Run gear set. And again, the Low Speed Gear is slightly weaker on the Quiet Run, but the opposing idler gear is stronger. So its a toss up.
Now I believe 1988+ cases used an upgraded Output shaft making these cases the strongest gear drive cases ever made by Toyota.
will the adapter plate seal the 90 weight oil in the tcase?
No, The oil is free to run through the bearings aiding in cooling. Depending on the weight of the GM oil, you might be able to just use it for both trans and t/case.
Regards,
BigMike
