Are you trying to replace yours, or do a new install? Most of the parts are available to rebuild one (except shafts). If a new install, you'll be much better off using a newer 5 speed. Lots more parts available and the NV3500 is probably the same torque capability with better gear spread. And if it's an 85 up truck with hydraulic clutch, you're already ahead.
A833's are not super rare but not common. I've picked up 2, turned down 2 and know where there is one running in a board memeber's truck. They were available in truck and Blazers. Some reading:
http://www.moparmusclemagazine.com/t...nny/index.html
http://www.moparmusclemagazine.com/t...dup/index.html
http://www.drivetrain.com/parts_cata...rhaul_kit.html
http://www.tbtrans.com/a833_4_speed_transmission_pa.htm
And here's some discussion:
http://www.dieselplace.com/forum/sho...d.php?t=371009
My 4wd trans has the TH400 type output shaft mated to a 208C case with a big (and probably specific) adapter, the type that mounts to the trans, case, and crossmember.
It appears all 4wd are iron cases, I know my 2wd case is aluminum. My 2wd uses a different length output and the TH350 type shaft.
Oh, and the bell housings are unique to the trans, some are Chevy bolt pattern in front, most are Mopar pattern, all but a few have a bigger input shaft retainer that will not fit standard Chevy bells, some are hydraulic clutch, etc. Be sure you get the bell that fits the trans and your application. My 2wd is an 85+ hydraulic Mopar pattern big retainer and my 4wd is earlier manual clutch, not sure which retainer.
The guy on the other board and I were discussing how difficult it would be to just swap output shafts 2wd to 4wd. I've got one of each, just no time or space to check it out.
Be sure to get the shifter, they are Hurst and are unique to the trans and application, and the 2wd and 4wd are different (one of the artivcles mentions this but they didn't really understand, one shifter is offset to clear the Tcase shifter and fit in the console. There is no current replacement shifter available.
Be warned that these are NOT the Hemi A833, the overdrive version will not live behind a big block.
Price? about $250. But if you have to ship one, they add up because of the bell and case adapter (which is cast iron and quite heavy). And shifter.