Need part for 88 suburban

[tomterrific]

This fine specimen of Detroit engineering is nees of an Air Diverter Valve (goes on Driver's side0. Mr Good Wrench says this part is a $175.00 Item. I'm hoping to find it for less. It looks like it should be about $5.00  Any ideas etc I'd appreciate. I guess I can get along without it until inspection is due.

BTW: Sure enjoyed "Rides last night. What wonderful skills you guys have. Those custom aluminum cars were just amazing.

[Sean]

Is it only on Suburbans, or do trucks and Blazers have it too?