I've read on here that they are an out of date design. What makes them old? I have a 292-509 that was in the 360 I bought and plan on using it until I build a 408.
Essentially and not to be a smart *** but their age. These cams were designed in the 70's. They work no doubt, but there are cams out now that can get you more HP and more vacuum at idle with a broader torque curve assuming the head can flow as high as the cam can lift the valve. Putting a .550 lift cam on head that stalls at .500 is a waste of time, money and motion.
There's a heck of a lot that goes into cam design other than just lift, duration and LCA including ramp design and asymmetrical lobe profiles. The geometry that goes into the newer stuff is very complex and more lift for a given duration can be obtained without wiping the lobes off or making a racket.
