Those valve spring pressures are way lower than I would use
I'm thinking 140 Lb. to 160 Lb. on the seats and 350 Lb.to 380 Lb. over the nose
I would want more lift for those duration also
I use to use the original Racer Brown for cams in my motors, I did buy and use both the STX20 and STX 21 cams, I wasn't smart enough to record and keep those cam specs though
I think the STX22 and STX 23 grinds were consider to be SS grinds and to be used on roller cams mainly