A couple key points at a glance...
93: First year of the 4th gen. 275hp LT1 V8 Z28 or 160hp 3.4 V6.
94: Switch to Mass Air from Speed Density. Aluminum driveshaft included with all 6-speed manual cars or automatic cars equipped with 3.23 gearing. All manual cars receive 3.42 gearing.
95: Optispark ignition upgraded
96: LT1 power bumped to 285hp with new dual-cat y-pipe. V6 bumped to 3.8 liters and 200hp (was available in LATE 95 in select states). RS model introduced for V6 cars - included ground effects and spoiler extensions. Ground effects could be had with Z28's under dealer-installed "F1" package. SS model introduced with 305hp includes ZR1 wheels, suspension upgrades, exhaust and induction, tall-lip spoiler and scooped hood.
97: Interior/dash upgraded, real tail lamps include amber turn signals, new 5 spoke wheel design.
98: New hood, headlights and front bumper. LS1 305hp V8 (Z28), 320hp (SS)
99: Small tweaks under the car include new computer, perimeter valve covers and composite gas tank.
00: New wheel designs for base/Z28 and SS. Interior colors switch from gray leather to ebony. Cloth interior has unique (ugly) pattern. AIR ("smog pump") added.
01: Bump in power to 310hp Z28, 325hp SS. EGR deletion, LS6 intake and "truck" cam round out the major engine changes. Upgrade clutch components are included.
02: Last year
This is all off the top of my head. There are other little things I'm sure I'm not remembering.