upgrade stock fans while doing the radiator?

Quicksilvers

Strange I have ran a CSF radiator and condenser on all the Z’s I have had and have never had any issues with leaking and saw a slight improvement in cooling ability. I would never run Mishimoto anything on my Z though just my preference as their products are made in China. I have used Redline water before it works well but I still would recommend using it with Genuine Nissan 50/50 blue coolant and never run straight water as it can form rust in your engine block with time. The Koyo radiator works well from what I have seen you just have to make provision for a condenser if you still want air conditioning in your Z. I would only upgrade to a high efficient dual fan set up if you are currently running forced induction.