Best source for 71 degree thermostat?

[mvliotta]

 

1 hour ago, Carlos_M said:

It should have a stamp on the side you should be able to see if you stick your head down or use a mirror.

Yep, 71 are the last two digits on the side. 

[Dudeland]

6 hours ago, alpinewhite318i said:

Does drilling the small help make the car run a little bit cooler and prevent air pockets from forming?

It won’t change the cooling. It may help bleeding the system. But largely it is so that you can drain the entire system by removing drain on your radiator. Otherwise the head and/or (I think) the heater core still retain coolant.   Please check with the Bmw sages on this forum.