This part exemplifies how Duralast provides innovative solutions to the market. The Duralast 37987 fits GM V8 engines from 1997-2003, nearly 5 million VIO.
This part mounts to the water pump, and when the water pump design was changed in 2003-2004 (varies by model), they moved away from an integrated thermostat to a separate thermostat and housing, the Duralast 524KT Thermostat Kit. GM shortly after that realized that the new pump would fit on the old vehicles and discontinued the old pump, with most aftermarket manufacturers following suit.
The problem this caused was once the pump was replaced with the new style, the 37987 Thermostat would no longer fit. The aftermarket had a thermostat for this pump, but there was no solution for housing, forcing the customer back to the dealer who only sold the housing with the thermostat.
This not only resulted in an inability to service the customer but also a return. Duralast provides a solution to this problem with the 524KT, along with proper cataloging of both items (524KT & 379187) for their respective applications.