There are upgrades you can do... depends on how much money you wanna spend. Google search it, 370's and titans usually go for performance.
I recently did a stock rebuild, using this kit:
http://www.oregonperformancetransmissio ... RE5R05A-RB
On two of the clutch packs, I think they put steel plates for a different variation of this tranny(maybe v-8?), so I had to re-use the stock steel ones, they weren't scorched, no problem.
I have about 2000 miles on the new parts now, including a 750mile trip averaging 85mph... it's running great and shifting smooth.
You may want to add a cooler and/or fan for the tranny, cheap insurance I think.
BTW, you don't HAVE to remove the exhaust to drop the 2WD tranny, but it's tight and you will want another person helping you. Believe it or not, I would say the most difficult part of the entire job was removing the rusted-on crossmember.