Thermostat spacer

I'm aware of that. I wouldn't recommend it though. The factory threaded holes have thicker bosses around them for additional strength. While drilling and tapping is easy, its gonna be damn thin, I'll betcha! You gotta be super careful how tight you thread anything in that hole.

Would be no big deal to have a boss type washer heli-acrced to the water pump, and/or , just make a spacer out of 1'' alum. ,I made one for a 406sbc once for return cooling lines from the rear of the heads , no biggee.