Martin, I'm now splitting my loop in two to add 2 mosfets blocks. To do this, I need to buy a 2nd pump and due to the space constraint (the pump will be installed under the PA120.3 radiator to keep the tubing short), I cannot get a aftermarket top with a top inlet.

So far, the only aftermarket blocks with side inlet would be the Koolance and Alphacool. However, I know that having a 90 degree bend in the inlet will reduce the performance a lot so I'm wondering if it's still a good idea to get a Alphacool or just use the stock top (it's not a problem since I use 3/8" ID tubing anyway) ?