I have .660 lift valve springs, and chromoly 7.425 push rods. Its 100% reccomended with my setup to let the car warm up due to the heavy duty valve train or else you could crack a valve spring.
I have read thread after thread on ls1tech with owners wondering why they dropped a valve or two after cold starts and driving and them not knowing you need to let the car warm up before driving it with the heavy duty valve train. Im talking about with my cam (.601/.609 112lsa). With a smaller cam im sure its nothing to worry about