From the "Features" page:
http://www.viperclub.org/menus/index_ivr.htm
These are changes that took place:
1997
RT/10
Viper GTS Blue with white stripes/blue interior accents
Viper Red/red interior accents
Sparkle silver wheel package standard
Polished wheel package (optional)
Gold wheel/tan interior package (optional)
Yellow wheel/red accent interior package (optional)
Lightweight engine with higher compression ratio and revised camshaft - 450 BHP (335 kW)
Driver and passenger air bags(c)
Power windows
GTS
Yellow wheel packag
New Red exterior color
1998
All
Tubular stainless headers (24 lbs. lighter, unclaimed + 4hp)
Camshaft change
Next-generation driver air bag passenger air bag on/off switch on dash
All: Silver exterior color
All: Change from smooth to "textured" dash
All: Small "Viper emblem" added to sill covers
All: Alarm reset switch
All: Silver exterior color
All: Mid-year changes:
PCV upgrade
RDC added a fan
RT/10
Hood updated to be same as GTS with NACA duct.
GTS
Optional Blue Center Stripes with Silver exterior color
Optional Silver Center Stripes with Red exterior color
GT2 Edition
Limited production run, in VIN sequence of 100 cars to Commemorate Le Mans victory.
100 car Le Mans victory commemorative GT-2 Run
White with Blue Stripes
Smooth intake tubes and K&N air filters (Rated at 460 HP)
Special GT-2 Badging and decals
Blue interior theme
Racing harnesses with Oreca Logo
Rear Wing (set neutral)
18" BBS Wheels with Viper logo center caps and Michelin Pilot Sport™ tires
"Assembly Camera" in glove compartment
Lower side sill "ground effects"
Front fender "winglets"
Trivia
GT-2 Viper only run of Vipers to date to be run down the line in VIN Sequence