[whittp]

The engine was built about 7 years ago and the shop owner has retired. The documentation for the build is at the new shop. Buying a new set of pushrods isn't a big deal for piece of mind and reliability. What are the performance trade offs? Is there a cam that will perform similar to what's in it now?

[Formulajones]

Originally Posted by whittp

The engine was built about 7 years ago and the shop owner has retired. The documentation for the build is at the new shop. Buying a new set of pushrods isn't a big deal for piece of mind and reliability. What are the performance trade offs? Is there a cam that will perform similar to what's in it now?

Without knowing what you have now there isn't a good answer. Generally though with the rollers carrying more lift under the curve, and having a good set of aluminum heads on the engine, it's going to be difficult to get the same performance from a flat tappet cam unless you get pretty wild on cam timing with the flat tappet, and then the whole question of drivability comes into play.
Yes you'll have to swap pushrods, and you'll need a different set of valve springs if you go flat tappet.

Personally, I'd stab a roller back in it, same thing you had since you were so happy with the performance of the engine, and either go with the Comp 857-S lifters or a set of Johnsons.

Sticking with the same cam profile keeps things simple for you. It's already been tuned and running for 7 years, you were happy with how it ran and performed, and you won't have to swap pushrods or valve springs.