I was thing a hydraulic roller would be quieter too, but it seems to be just about as loud as a solid roller, or maybe I'm just hearing the roller rocker arms, rollerized timing gear, and roller thrust bushing?

I think a rev-kit where the springs press on the top of the lifter body would help if you want to run high RPM with a hydraulic cam?

I can't swear to anything in a big block but my Drag Pak Challenger has a hydraulic roller and you shift it at 7000. It also has very light springs. Big block valves would be heavier.

Time for a dyno test!! There is an article on a BBC motor, about 560 cubes? making 1,000 hp, and running hydraulic lifters. If those guys can do that, the Mope should be able to run 7,000 with the right parts. I would think a high ratio rocker would help significantly too.