[blykins]

Putting out 550hp may not sound like much to some, but it requires a little bit of effort, in the way of cubic inches, cam selection, cylinder heads, etc, etc.

Most of the cams that are used in these engines are healthy flat cams or nicely matched roller cams. Those cams with .600-.650" lift will put factory parts to the test, especially without hardened shafts, end stands, etc, etc.

Non-adjustable factory rockers are laughingly inappropriate in this type of scenario, and the factory adjustable rockers that I've seen on Edelbrock heads don't provide good rocker arm to valve tip geometry.

In my mind, at the very least, upgraded stands and shafts should be used, then you're worrying about the cast bodies of the rocker arms and the adjusters holding up.

In a 300-350hp hydraulic flat tappet engine, I could see where these would be appropriate. In a $17k-18k all-aluminum, 550-600hp roller engine, these are not even a consideration on my builds. I wouldn't want that build compromised on a set of cheap rockers. Even with an aesthetics standpoint, I'd hate to show off my $5000 engine block, $3000 set of heads, ported and matched intake manifold, then pull off the valve covers to see a set of 40 year old cast iron rocker stands and rocker bodies....

Jeff, I know I spoke with you on the phone about this, but I don't feel like I stated my case thoroughly enough. The benefit may not solely be on the horsepower side, but it is very much on the reliability side.