What are the differances in tcase types?

[JWHurst]

I have two tcases for my project truck/land cruiser.  One is the original 1982 pickup's with the shifter located ontop of the tcase.  The other has the shifter forks that come forward into the 5-speed case and then has the shifter for both.  From counting the bolt patterns, they both appear to be gear type not chain.  
  My question is one tcase stronger than the other?  I've swapped out the 22R engine to a Chevy 350 5.7L 4-bolt and the stock 5-speed has granaded three times now.  So, I've picked up a 1993 NV4500 for it and will have to adapt one of the tcases to it.  Which one would you use?  I believe the better one to use would be the original one since it's shifter is mounted ontop of the tcase.  If I use the other one, the adapter would have to have a shifter hole in it.  What do you think?  

One more question...  When I go to put in the NV4500 with which ever tcase, will the adapter plate seal the 90 weight oil in the tcase?  I'm told that I have to use GM's oil in the NV4500.  It's aparently a different weight/type.

[BigMike]

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