Although physically you can swap the followers no doubt for the std hydraulic items, the cam may well have a quietning ramp on the lobes for solid tappets, shouldn't really be a problem though, but then neither are a good set of solid, adjusties like you have or a shim adjusty set is easy enough to make for the cvh if no one does it already, as loads of clearance for them measuring wise, these stay in gap so long might be a better bet if you don't want to go hydraulic for some reason, such as really wild cam etc in the future.
tabetha