installing the CI valve spring CSC-STY-SPG

The inside Dia of this spring is .925, but the Dia of the spring seat boss is about .975. on a 72 250 head. Spring seat cutters do a .625 or so ID which gives a bunch of room for hammering around. Any one here dealt with this? There are spring seat cups, but they are hardened and spendy. Need Help!
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This is the single spring with damper from Mike. Nice lite spring with a rate that should take the engine to 6000 or so installed correctly-Just the stock seat is .050 dia. too big so the spring won't seat and the seat cutters I can find seem to be for dual springs taking the dia down too far. Some one here has to have used these. Local shop said they had a machine that would cut any seat I wanted, but was asking 12$ a seat!! Seemed pretty high to take off .025 wide by about .060 thick.
Cut off a piece of 1 1/2 dia bar stock and was going to start making a type of fly cutter piloted off the guide both ID and OD.
Is there a better way??
My Way

Do you have any pictures of the problem it would help?

Haven't learned how to move this stuff around after loading the pics.
Anyway-- The head has the spring seat machined at the base of the guide for the spring to sit in-on the stock head that is a .975 ID and locates the stock spring. These single springs with dampener have an ID of about .925 so when you set the new spring in the old seat there is a hang edge of about .050-------That's just going to grind away. So if I wasn't so cheap I'd have the machine shop trim em for about the price of a cyl bore job on a 6 block-12$ a seat-24$ a cyl x 6=144$. Is there a better way?
Somebody has got to have done this before.
My Way

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Been looking-What I find has been for dual springs-all smaller to the point of not providing enough centering.

You did not mention what the OD is that you need but this cutter maybe one that will work for your project, or if you can find someone in your area with a Bridgeport Mill they could set it up and cut them too. Good luck

https://www.google.com/shopping/product ... NcCEKYrMA4

Take everything to an automotive machine shop & let them do the work.
It will be less costly in the long run & done right.

Thanks guys
Bubba those cutters take the seat down to .630 which I think is to far and will let the spring wonder around. Still looking though.
Wsa your right--it just seemed high priced @ 144$ to seat 60$ springs. + two trips 120 miles of driving!!
Still working on home made cutter. Just my way
"O" and you can't just modify those seat cutters with the carbide blades.
My Way