When I was in high school several of my friends were Olds freaks. I liked them so well that I bought a GMC 550 that was born with an Olds 371. It was common to put in solid lifters in those days simply because the radical cams were designed for solid lifters. These were usually high lift cams with a lot more duration than stock. I have been told that a cam for hydraulic lifters started lifting more abruptly than a solid lifter cam, but I never tried measuring the difference. I think this is the "clearance ramp" that Jerry is talking about. We had the idea that solid lifters were better at high RPMs, but again the really radical cams were solid lifter cams. I also played with GMC and Ford Y-Blocks which were born with solid lifters. Back in the 50's, a Y-block would wind up a lot higher than GM V8s that were born with hydraulic lifters. But there were other factors that we didn't consider.
I don't know much about cams past the Olds Rocket years, but I don't think anyone could tell the difference by looking at a cam for mild street hydraulic or a cam for mild street solids. I think a lot of engines were retrofitted with solids back in my day just for bragging rights. However, there were guys that went to the old Double Eagle strip in San Antonio and the serious competitors had solid lifters. I was down there with Y-Blocks that were born with solids. There is still a group of serious Y-Block guys. They are very serious about the sport and they now run roller cams. I'm not a participant, but I enjoy reading their literature.
