Whats the height of the Lian Li PC70 ? With the pump at bottom and rad over the top that may be already a pretty good height. If you have 1/2" tubing all the way it's good though, it won't add much lift.
If you can try to put one pump at bottom and one pump at top.
Or each pump at opposite parts of the circuit, then to compare this with both pumps next to each other...
Results may be very interesting
