To expand on @Stan Galat's scholarly details regarding valve lift, rocker arm ratio consistency and horsepower potential, consider the results recounted here with the ne plus ultra 4-cam engines.
My initial reaction was stunned wonderment: If you take an original, quarter-million-dollar 547/1 4-cam engine, hire the foremost expert available and have him punch it out to 1792ccs, increase the compression ratio to 10.4-1, install custom Nikasil cylinders, Dilivar head studs, custom rods, lightweight wrist pins and ultra-thin rings, special valve guides, custom valves, 911 valve springs with titanium retainers, a lightened flywheel and a full dual electronic MSD box with computer-adjusted spark table . . .
you'll get almost as much power as a Standard-issue CB Performance 1915cc Type1.
But then with the header it's almost as good as a 2110!
My second thought was stunned wonderment at the original "One Dot" 1500 Spyder cam, which reportedly provided 10mm lift at the valve.
AKA .393 valve lift.
—In an engine that reportedly produced 110hp at 6200 RPM and routinely exceeded 7500 RPM on the track.
By comparison, the Engle W125 cam in my 1914 engine reportedly makes (with 1.1 ratio rockers) .460 valve lift and 262 degrees duration which, combined with big-valve heads, dual springs, big Webers and a bunch of other cool stuff results in 120 peak HP at 5500 and about the same torque at 4000.
What might cam specs like that do to a 4-cam? Would it rev to 12,000? Make 170hp out of 1600ccs? Blow up?
I guess my point is, if you really have a stock cam in your engine (and I'd make very sure I did know what the cam's specs were before proceeding), ratio rockers are an excellent way to start to wake it up. But as @ALB advises, you also will need to upgrade your intake and exhaust to make use of it.