I was saying that, BUT, It just fits. I had to fine the block till the PCB length and remove the backplate. (I did a bit less so the GPU is completely blocked). This means that using the 263mm blocks from Watercool and AquaComputer should be ok (I have to check of course).
I still have to send them to RMA the pump. Actually there was a metal piece inside the impeller. Removing it seems now has resolved the weird sound.
BUT still, because it has an incredible head pressure, you can hear the splash at speed higher than 50% (I keep it between 15% - 90l/h and 40% - 160l/h).
Man, it's WAY quiet than the DDC, and doesn't have the high pitch annoying noise. I need to test it more though.
To mount it on the 1U Reservoir, YOU NEED 45mm M4 screws.
In the last picture you can see on top the 3.1 and in the bottom the rewired 3.25 PMW just show you that you can have just one cable if your motherboard/controller support 2A.
With the VTX pump, the temp are the same that with the other 2DDC though. I think when I will change the GPU block I'll put back the DDC 3.1. The 3.25 and VTX are too pwerful!