I don't have a hotside in front of me but maybe someone will refresh my memory as to whether two of the holes on the hotside flange are internally tapped for bolts, whereas the other two are drilled but not threaded. That is there are two studs and two bolts. Or, have I been drinking too much Mezcal?

 

This maybe correct SPARKY, the 2 closest to the radiator look to be just holes and my tap/chaser tool wouldn't start in them. And I also had bolts/nuts in them but I thought it was bc I didn't want to hassle with broken bolts that could ruin my hotside next time. Will just bolts and nuts be fine at the 2 holes closest to the rad?