F*ck, I hit back again... was the Intellimouse
JD, I see what you're saying, but I think it is just a matter of matching the manifold outlet shape to the target flow rate (lol, did I say "just"?). Imagine a 1 x 50mm outlet for a moment... don't you think that even at low flow rates, the water would still flow pretty evenly?
I will try to find the right shape by first making a test manifold, then hooking my pump to it (plus rad), and seeing how well the water flows evenly.
Oops, I forgot to mention I am using a pump with 8.5m of head

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CSL Velocity T-3.