My 62 122 has a B20 engine and I recently discovered that my water pump is leaking. I ordered the water pump from Amazon, Gates brand $27. When I ordered it I said it was for a 1970 142 (just a random selection of year) not a 1962 B18 for obvious reasons. I haven't done the repair yet and am thinking I should change the thermostat as well. Same info brought up a gates 180 degree thermo for $9. Doesn't say if the gasket comes with it, but they have those separtely. 2 Questions: is there any difference between the B18 and B20 waterpumps or thermostats? What years and models came with a B20? I have no idea what year this particular block was made. It was installed in 1994.