I think only the spline count (and associated parts like side gears, spider gears, diff case) changed for the 97 model year, but the ring and pinion gears SHOULD all interchange. IIRC, the truck gears were slightly larger at 8-3/8 vs. true 8.25, but it SHOULD all work. I think as long as you're swapping the whole diff chunk, any housing should be fine. The differential had to be changed on the 2.45 gears to put some meat back in to the ring gear, as the pinion is so large the ring would be too thin otherwise. There were some NOS 2.45 SG's on epay a couple years back, so that supply still seems to be out there. May as well put some good stuff in if you're doing that surgery. I also hope most of the driving will be highway, as 2.45's are anti-mileage gears around town. BTDT.

Clair