[tirod]

It's touched on, there's a lot more to picking a rocker. If someone is buying a built crate motor, then let the guy who's backing it with a warranty make the choice. It's his money on the line if it fails, and he will make a knowledgeable choice based on not having you come back with a problem. In the $5000 dollar and up range, I wouldn't expect to even be allowed to micromanage the choice of which rocker to use.

Why? As was mentioned, it's all about valve train geometry. Stock parts shouldn't be reasonably expected to work in a valvetrain where all the other parts were selected to enhance the timing and lift. It's like insisting a new Cobra be put on 15X6 steel rims with 2 ply bias tires. Nobody raced them that way, it was Halibrands and Goodyear billboards, or go home.

Rockers not only have bearings to reduce friction, the more important function they serve is to be more rigid to reduce harmonics; to have better leverage, enhancing intake timing and lift; and to be much stronger, to handle higher spring pressures. Typically they're made from aluminum, to reduce the reciprocating weight and raise the float rpm limit. They are adjustable, to get them to work at the appropriate height for the valve and spring package, and have stronger tips to handle the more violent action of high performance cam profiles.

At least, that's what all the rocker arm makers, magazine writers, and hot rod engine builders who write books have been saying for over 30 years. I don't buy the Brand koolaid, but they have a consistent message.

In this case, a 550 hp 427 FE isn't a mild build at all, and having it go down in a few thousand miles to save $200 is false economy. Once the valve train is set up, a stock rocker might not even be able to physically function - it only works with stock factory valvetrain stuff, and nobody gets 550 hp from those.

There's a limit to how far a business can bend over backwards satisfying a customer. Once it starts costing them profit, doing things that damage their reputation, and against good practices of their trade, they politely excuse themselves and move on. Customers who have so much knowledge they feel they can dictate terms on small but influential areas are invited to try it themselves - at their expense.

Hot rods are NOT a collection of the coolest or least expensive parts. They are a dynamic assembly that has to interoperate with each other, and that creates synergy - the result is more than just the adding together, it's a mulitplication. Getting 550hp out of a 427 FE will require it, and only experience and knowledge of what works best together with other parts will get that result.

Chinese menu motors fill local car shows, but the results are seen at the strip and track. The cream rises to the top, and it takes a lot to get there.