Colville Washington

I'm hoping to get to Mount Spokane this spring after my knee surgery on Friday. I'll lube the motor, and light her off. She needs some break in miles. I'm continuing my Dart build behind enemy lines in western Washington.
Spokane Valley here. Looking for a rebuildable heater box for a 70 Dart Non-A/C car. Sorry to cut in but saw you all were NW people. Thank You !