[Gregski]

so got the truck in and performed the extraction, and there are Lessons Learned here

1. GM made at least two different water pumps one with a smaller 1.88" diameter thermostat opening and another with the larger 2.05" diameter thermostat housing (after buying the wrong smaller one first thinking it would make sense for the 4.8L I exchanged it for the larger one which was the one I needed for my 2001 GMC)

2. GM also made a couple different thermostat designs and also after buying not one but two wrong style ones I finally got the correct one, the correct one for the earlier 1999-04 trucks seems to be the one where the stat and the housing are one unit.