valve spring height question

i also have another option. I called compcams tech line i told him my problem and he recomended me using #972 spring instead of the #911 spring.

#972 -16
rate 308lbs
1.060" ID 1.460" OD
seat load 124lbs at 1.800"
open load 293lbs at 1.250"
coil bind height 1.195"
with damper


this would solve installed height i could shim to spec.
any see any problems with using these springs with 906 heads and a 68 335HP 458 lift MP cam? thanks