On the Thermostat housing, you're going to find .... ... that the two back bolts (5/16") are a PITA to get at ... .. without the right tool. A 5/16" or 8mm swivel ratchet wrench would also do the job. When you snap it loose and begin to back the bolt out, it's going to raise and start bumping into the black housing of the intake (round black disk). You'll want to switch to an open end wrench to help it along until it does bump into the black plastic housing. I was able to lean the Thermostat Housing forward and backwards a bit while lifting up on it ... and with a pair of needle nose pliers make the remaining few turns to loosen the bolts completely. Careful not to drop anything down into the housing intake chamber. That would suck! The two back bolts need to either be replaced with something shorter or shaved down a bit as to ease installation. I opted to just put two of the set of bolts on the grinder and shaved them down and sandblasted them to clean up the rust a bit.