That was what I was thinking. Could be to prevent someone from sticking a hydraulic cam in a solid block, though. It does seem odd, Patrick used to offer a hydraulic cam.
Now for personal opnion, I like the solids. They sound better to me, and nothing really screams "Hi-Perfomance Chevy" than a solid lifter cam a tickin' away under the hood. There's an old saying, "Nothing strikes fear in the hearts of Ford and Hemi drivers more than the sound of a Solid Lifter Chevy".

Bill Burmeister