Ok, I just got finished installing new 454 mercruiser longblocks, I have new raw water pumps, but am wondering if I should replace the water pumps on the engine? I was told if they werent leaking leave them alone, is this good advice?

If they're new why replace them, stock mtrs no need..... if its not broke ..........ect

If they are not leaking, there is no reason to replace them. Leaking is the first sign that they are getting bad.

Raw water pumps or circulating pumps?

Circulating, the raw pumps are new.

Like they said, leave them be.