[blykins]

If you like the way the engine performed with that cam, just buy another one.

If you change to a roller, you'll have to change valve springs, distributor gear, lifters, pushrods, etc. It's not a quick and easy swap.

As for the valve cover flange, you will need to have your machinist mill the valve cover flange of the intake down to match the heads. Just take a measurement and correct it.