Comp 980s with damper (inner spring) don't reuse the stock cups. I think it's 980-12. Replace the seals on the intake sides only as the exhaust side does not use them. You should be able to get them as a parts store that carries Compatition Cams parts. Do a search there is alot of discussion on springs but the general consences is the 980s, that's what I used.
The 980s installed to stock height is at the top end of stock specs and the use of the damper spring should provide longer life to those that routinely run their cars to 5400 or so going thru the lights...
I kinda got lucky with my springs.
I had placed an order for valve springs and got the wrong numbered springs for the cam I was using in a SBC. I decided to keep them for sometime down the road rebuild on an SBC.
They turned out to be 980-16.
So I'll have 4 left over.
May buy 2 more sets of 16 to fill out another set.
Not that I'll need them. but someone else might.
I was curious if the pressures had been normalized for the same height....we use a kinda odd bal height and lots of times pressures are shown at 1.7 instead of whatever the fricking height is on a buick.