360 magnum. 1 piston lower in cylinder??

Ok. So the factory Magnum 9.0:1 (thin head gasket) ain't getting it done. Let's say I spring for new slugs. These are going to occupy more real estate up top. Right?
Won't that create issues with valve to piston clearance as well as valvetrain/spring geometry? Shorter pushrods, different valvespring, keepers......$$$$$$$$$$$$$$$$