These were saved from the Chrysler/Shelby Development center just before they closed up in 1989. 
 
These valves were custom made for the Shelby Can-Am program that was running at that time. 
 
There are 13 intake valves and 13 exhaust valves.   Obviously they produced one extra (per intake/exh) so you'd have one good spare valve.     
 
If you own a Shelby Can-Am race car from that era, this is a very rare opportunity for you to own a cool piece of Shelby Skunkworks history! 
 
Price is for all 26 valves.