416 build what cam ?

Don;t bother with bigger valves unless you're porting the heads. IMO - better to simply replace the heads because money-wise you're going to spend within some hundreds of a better set of new heads on updating the old ones. Save up if you need to because that choice also affects the piston choices you have... The .528 IMO is way too small. It will work, but it's not enough even with the wheezy factory heads. You will want to look at something at least 245° @ .050 and around .550 lift.