One other consideration- - - -regrinding a valve seat sinks the valve deeper into the head, and also lengthens the installed height of the spring. There are ways to check and correct that situation that any machinist worthy of the name should be able to do. It's entirely possible that installing those springs without shimming them to the specified assembled height might be a fudge factor that will work in your favor. Nothing beats hands-on measurements instead of speculation on "possibilities" in a chat room, though! I've used the quill on a drill press and a bathroom scale to check spring pressures at times! LOL!
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!