RE: Muggy break-in
If you have put about a 1/2 gallon through it at that temp, it is very hard on the motor, but your motor is probly still ok for the time being, but if i were you i would lean out the hsn, set it to 3 to 3.5 turns out, then run it, let it warm up but check your temp regularly, once you can take a good run and your temp is between 220F and 260F and good smoke then you are in the safe zone, this is were you want it at all the time. Also a good tip is to mark your bottom dead center (piston at the bottom of the stroke) and when you park the truck make sure your piston is at BDC, this will keep it out of the pinch point and put less strain on your engine as well.