anyone use a comp roller cam and lifters in LA small block

I am using the factory roller setup with the 280HR comp retro fit hyd roller cam. The engine it is and I'm finishing the project now so I havent' run it yet. I have heard about issues with the mopar roller lifters at high rpm but not sure I understand the reasoning. Don't the Mopar crate motors use a magnum block and stock roller lifter/dogbone setup? I haven't heard of the crate engines having issue over 6000.

It must like 340 Mopar said and the issue is with weak valve springs.

Steve