newer pump seal, new oil, and gear oil still turns white

Water in trans oil.....

The water pump has an inboard bearing that is pressed into the right side case half and should be replaced when the new bearing and seal are pressed on the shaft. Plus, properly pressing the new bearing and seal on the impeller shaft determines it's life......

Another possibility is that the shaft is grooved and lets water leak past. On mine I replaced the 2 seals, bearing, and shaft because the seals and shaft were bad and I was in the area so the bearing was changed as well. With an 89 there may be only one seal. Either way, did you check the water pump shaft for problems when you replaced the seal?

Another option is the breather tube, or worst case is a leak/crack in the water jacket.