Dave, the only real way to know what your P/V is is to use clay on the pistons and use the springs you are going to run and the head gasket you are going to run at the lash you want to run and turn it over.

If you do the soft spring method you will have way more clearance than you think you do. This is because no matter what rocker you have, if it’s built correctly the ratio will be .3-.5 or so higher than the nominal ratio. Has to be because all rockers flex under load.

I’ve seen guys machine the valve pockets because they did the soft spring deal, or change the ICL because they used soft springs when in reality under actual spring loads they had more than enough clearance.

I stopped using soft springs to check P/V in about 1986. It’s just not a good way to check that.