Hi, I'm older, and a stick doesn't appeal to me as much as it once did. Yeah, it is very possible to put in a manual trans, but you have a lot of work to do to get it there. Stuff I can think of are : Clutch pedal,clutch master cylinder, lines,Adapter plate, Tremec 6 speed(might as well go for the gusto, at least on the street!), crossmember refab, driveshaft refab, speedo hassles. The list is a long one.Lots of fabrication will be needed. Again, virtually ANYTHING is possible, but you have to decide what is beneficial to YOU. If you do decide to go this way,It will be a one off bad boy, to be sure. Imagine the 6 grand holeshots you could pull! I don't know how much of that the 8.5 could take,but that's another issue....
Have fun!