Taken from the "Features" page under "Viper Registry" on this site...Only year where GTS had more horsepower.
1996
RT/10
Exterior design themes: Red with yellow wheels, Black with silver stripe and silver wheels, White with blue stripe and white wheels, stripes are "sabre-tipped"
Higher output engine (415 hp, 488 lb.-ft. torque)
All-aluminum front and rear suspension systems
Rear exit exhaust introduced to U.S. RT/10's
Five-spoke cast wheels with MXX3 Michelin Tires
Trivia:
First year of production at Connner Avenue Assembly Plant (CAAP) (Formerly a Champion Spark Plug facility).
Reverb canister removed from corrugated intake hoses
OBD-II
Exhaust and intake changes allowed engine to be tuned to 415 hp.
The inner hood of is from the upcoming GTS and has the openings to facilitate louvres.
GTS
Coupe body style introduced spring 1996
Viper GTS Blue with white stripe color scheme, completely new "lightweight" engine with higher compression ratio and revised camshaft and forged pistons for increased power - 450 bhp (335 kW)
New Body Features:
Coupe (hardtop and hatchglass) body style
NACA hood duct
Hood louvres
Rear venting outboard from tail the taillights
Racing style quick-release aluminum fuel filler door
High-mounted stoplight features LED backlit Viper emblem
Power (glass) windows
External door "handles"
Five-spoke polished cast aluminum wheels
Completely new black interior featuring:
Manually adjustable accelerator, brake and clutch pedals contolled by knob located under instrument panel
Rotating light switch (replaced push-pull knob of earlier models)
New dash and gauge layout featuring 200 mph speedometer, 7,000-RPM tachometer, engine coolant gauge, oil pressure gauge, fuel gauge and volt meter
AM/FM stereo CD sound system
Storage compartments between seats featuring lower storage bin and upper storage pouch.
Driver and passenger side air bags
Black seats by new manufacturer (Johnson Controls)
Air conditioning becomes standard and now includes a "recirculation" feature.
Trivia:
Hood changed from RTM (Resin Transfer Mold) to SMC (Sheet Molded Compound)
First model with molded key heads with Viper logo
Only model that stripes continue through the license plate area.
Radio moved above climate controls (from below) for easier access.