Yes, you would get better pressure, but that would not necessarily reflect in significantly better temps. Flow rate vs temps follows a pretty harsh diminishing returns scale. Once there is "enough" flow rate, the additional flow rate does little, if any to improve temps.
A D5@12v is plenty for a cpu, block, and a rad.
TROOPER: Caselabs M8, i5 3570k, 16gb DDR3, 2x7970, X-1050
TARDIS: 750D, i5 2550k, 8gb DDR3, 7970, AX850, 8TB storage
CUBE: INWIN BQS656, Celeron something?, 4gb RAM, 32gb SSD