One thing you will probably notice is that overall the engine will run cooler and may not achieve proper operating temp. You can try to compensate with the water thermostat but eventually you'll want to get the
oil cooler thermostat.
UNLESS YOU ARE RUNNING HIGH RPMS FOR EXTENDED PERIODS (as in racing) THE
OIL COOLER IS FOR LOOKS. Some people have bypassed it.
Had I kept mine I would have added the thermostat at the beginning of the next season.