98 is ~.25" longer
The receiver ring is ~.2" thicker
The barrel threads are larger on the 98
The 96 cock when closing the bolt
The 98 cock 85% when opening the bolt
The 96 has two locking lugs
The 98 has a third safety lug
The 98 barrel seats on an internal web in the receiver AND the barrel shoulder
The 96 barrel seats on the barrel shoulder
Also,
The 98 Bolt shroud has a captive spring latch
The 96 does not
The 98 shroud has a gas deflecting flange
The 96 does not
The 98 has an aligning shoulder in the front of the firing pin
The 96 has a aligning notch under the bolt body for the sear (may be confusing this with a 95 mauser)
The 98 comes in several varieties, standard, intermediate most commonly, magnum, short, and other rarities less so.
The 96 is more or less standard