Space wasn't an issue as I had 3 Swifty rads in a series/parallel combination before the HC
I was more concerned with pressure drop across the system. I've found pressure drop measured on one of the BIX's but haven't seen anything on the other. Can't remember which is which right now but no matter.
A complete secondary loop for HD and GPU is a future plan but gonna require building another custom case which is yet another future plan. Building my own case from the ground up with chromoly as chassis and CF as panels.
BTW- thanks for the reply again fhorst. The simple questions don't seem to be answered here too often. I'm tryin to play catch up oon my physics and such but it's been 20 years since I had physics

Some of these guys here are making me realise how much I've forgotten