340 xhead spring shimming, height and pocket question(s)

More math.....if my intake height is 1.6576" and my cams lobe lift is
0.329" call it 0.495" valve lift.
So if I take my inst height and subtract valve lift, I get 1.1626", coil bind is 1.125" pretty close, too close?
Open psi at 1.200"= 284 lbs, so obviously at 1.1626"(theoretical full open) the psi is 284 PLUS the extra 12.68, so 297 lb at full open.
Anyone see issues with this? Gonna chk cam/spring specs.
Thanks
Subtract your valve lash from the lift.