i have a rebuilt omc 5.7l gm( approx. 10 hours) and i replaced the starboard manifold and riser. with engine running on the muffs and temp gauge reading 160 the new manifold feels warmer to the touch than the port one. is this normal? the new manifold is from sierra, not sure were the port one is from, came with the boat. new manifold for port side on order.