Before I plugged the bypass and drilled a 1/8” hole it took a lot longer to heat up. The 1/2” bypass hose let to much circulate I’m guessing. It also appeared let too much circulate after the thermostat was open causing over heating when in traffic.

Racers have been using restrictor washers for years…

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Another interesting subject (thermostats):

Years ago, when mine failed closed (VERY long ride home, stopping every few miles to let the motor cool), I investigated the new ‘fail open’ models.  None available for Y-Blocks then that were not designed to hold engine temp at modern higher levels (more efficient).

6 VOLTS/POS. GRD. NW INDIANA