how much cam with performer rpm heads?

The OP could have been curious about the same thing I am, which resulted in me finding this thread as well.
My questions is this - how much lift can the RPM heads handle - regarding the retainer to guide clearance (not the factory valve spring lift limit, which is stated obviously in the marketing material.... Ya know?

So if anyone has an answer to that one, lemme know and :poke: at ya all....