Pushrod problem with Speedmaster heads

Yup, i have the same issue.
My question.
* I am mocking up on a stock 5.9

just to get a look at the amount I’ve ground away + push rod length.
Been chewin away at the heads and all clear. But, the engine I’m going to actually install on, the cam has a higher lift. And
* will an aftermarket cam have the same base circle for clearance and push rod length considerations?
When I go to swap out heads on the intended recipient engine, I would like no surprises.