This to replace the thermostats and sensors.
The 24, 1/4" bolts (7/16 socket head).
If just changing the head gasket, no need to remove them.
The other 14 bolts hold the head in place (don't remember the size, looks like 3/8" with a 9/16 socket head).
Be sure and take pictures if you get it and please ask questions when repairing.