[Marine One]

Neither. Why would you want to install a bigger bump stick, then try to eliminate the extra lift?

You would not need to change pushrods unless the diameter of the base circle changed (base circle, not lobe).

By raising the base where the rocker sits, you affect how the rocker contacts the top of he valve stem, which impacts valvetrane geometry...good or bad depending on where everything was at before you started changing things.