the reason you want a couple holes drilled in the edge of your thermastate is a good one it will save your engine when the thremastate sticks trust me it does happen i wont run one without a few holes in the edge after overheating two engines over the years one 68 chevy one new boat with a chevy 4 banger that ran just hot enuff to burn the head up after a year the guage never went over 190 it always ran just a little hot runs perfect now and yes the therm. is drilled
