How many 1998 produced?
You might try contacting Dodge Corporate for your answer.
They made about 379 Viper R/T 10's in 98, not sure on the GTS coupe, probably in the 700 to 800 range.
I think it was 837 for the GTS
Looking for a Used Viper in your area?
CarGurus has 256 nationwide Viper listings starting at $29,995.
Search Dodge Viper Questions
Dodge Viper Experts