I'm ready to change my hoses and note that Clarks-Garage.com suggests a coolant system pressurizer to blow out the last of the air in the system. I was wondering if Motiv sells adapters (or if one could be made from an old radiator cap) to pressurize the system that way.

 

A Radiator cap would be tough to modify to work since it has the pressure limit spring and bypass deal, the normal sealing surface is the lower shoulder around the smaller opening in the filler neck.
I've just capped the opening with my hand and blown into the overflow hose before. It works pretty well.

 

Why waste the time when Autozone will lend you the proper tool for no charge???

 

Bingo.