Thanks for the update, I was curious about cranking compression. One reason I asked is that seems like your 60' time was a little anemic for such a combination.
Yes you would expect the pressure to increase with advancing the cam. How much? I believe I could move and check it, faster and more accurately to determine the change, than I could could calculate it on paper; but that's me.
In general I have found that moving the cam has less effect, then something like milling the heads for a point of compression reduction. I have no experience with running aluminum heads, but I see some posts related to a higher cranking comp tolerance. That said, I have a current iron head 440 that is around 185psi that runs on pump gas with the timing, etc. combination.
Higher ratio rockers can give a nice semi-external tuning option assuming you've got plenty of valve to piston clearance and there is no rocker to retainer clearance issues; diff length pushrods may be required also, but you'll have to trial check. However, being a semi-old index racer type, I would recommend just changing the cam position and run it first and see what happens. One change at time and see what it really does.
