Was that .441 lift measured at the cam lobe or at the valve? If it was at the lobe then assuming a 1.5 rocker you certainly would have coil bind with .661 at the valve.

I would consult with any of the major aftermarket cam grinders and ask for an RV cam for your PowerWagon applications and get the matching springs. You could install the cam & lifters without pulling the heads, but why not freshen the top end (valve job) at the same time?

JMHO