Quote:

Any harm in drilling a 1/8" hole if it already has one?



The difference between a drilled hole and a one have valve is no flow during warm up.

That is why out of the box thermostats do not have a hole.

It may be more of a chore to rid of air after the initial fill but after a couple cycles the air will find it's way to the radiator cap or coolant reservoir.

One vote here for faster warm up.

69 Super Bee, 93 Mustang LX, 04 Allure Super