I just replaced my water pump yesterday. No sealant was used and there don't seem to be any leaks after about 50 miles of driving. Four seals came with the pump - big cylindrical and small cylindrical for pump to head seal; large O and small O for the heater pipes.

I found it easiest to mount the lower pipe to the pump before bringing the pump up to the block. Once the pump was gently moved into place the lower pipe bolt was loosely installed in the block. Then I used a BF screwdriver against the timing gear cover to lift the pump vertically against the head and got the three non-hose-clamping pump bolts installed. Next was jamming the top heater pipe into the side of the pump -- hardest part of the job. I ended up tapping the pipe into the pump using a small screwdriver against the rib on the pipe. Finally the bottom pipe fastener was tightened and radiator reinstalled.

BTW, all exposed surfaces on the block, head and heater pipes were wire brushed clean before attemping to install the new pump.

Joe M in WV