Installed spring height question
I have an Olds 455 that I have installed an Comp extreme cam. The valve spring they recommend requires an installed height of 1.700 the factory installed height is 1.670.
How is the best way to get there? I have seen one recommendation to mill the spring seat down 0.030 and I have had another recommendation to mill the mill down the valve seat during a valve job thus increasing the valve stem height.
My concern with the second option is that it would screw up the rocker geometry. The machine shop I talked to said machining the valve seat down 0.030 had the potential to hit water jackets.
Anyone out there got any suggestion?