I was going to go solid flat tappet last time I went through the 468bb in the Chevelle. After some research, I learned that there is some question as to the current quality of the aftermarket cast iron flat tappet cam blanks. It seems that many companies use blanks that come on boats from very far away, and quality can be hit or miss.
For this reason I went with a Solid Roller cam on a billet blank, just like the engine before. Although the current HP standard,rollers are not without there share of issues in a performance application. Hydro roller lifters are HEAVY, and due to being hydraulic, valve spring pressures need to stay on the moderate side. Most hydro rollers are limited to 5500 to 6000 RPM's in pushrod engines. If you over rev and float the valves on a roller cam, you stand a good chance of doing seriouse damage to the roller portion of the lifter, and eventualy your cam.
Solid Roller lifters wont put up with bouncing up and down on the lobe much either, but on a solid this is usualy due to excessive lash causing the wheel on the lifter to lose contact with the cam lobe, eventualy this will destroy the wheel, needle bearings for the lifter wheel and the cam lobe. Excessive idle time is also realy bad for a solid roller due to massive valve spring pressure and lack of lube to the wheel areas of the lifter.
Bottom line is IMHO, roller lifters should be periodicaly checked in a performance engine. This is something that I know well since I was guilty of saying "oh their fine" until one day 4 years ago a lifter wheel shattered at 6800 RPM's and broke the cam in 3 peices and took a hunk of the lifter valley out the size of a softball. The lifters were high end Iskies, but I had not checked them for 5 years.
