Chevrolet 2000 Corvette Owner's Manual page 337

Scheduled Maintenance
150,000 Miles (240 000 km)
j
Drain, flush and refill the cooling system (or every 60 months since last
service, whichever occurs first). See "Engine Coolant" in the Index for
what to use.
An Emission Control Service.
7-12
DATE
ACTUAL
SERVICED BY:
MILEAGE