I'd need to make spacers 1/2" tall to make up for the different keeper groove position. That would look pretty oddball, even if I'm the only one who knows it's there under the valve cover. Making another keeper groove is "Machining 101" once the holding fixture for the lathe chuck is made, and the process will be exactly the same for all the valves. For reference- - - -the Chevy OEM valve with the 1.94" diameter and a 30 degree seat angle part number is 3835519.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!