If both bearing outer races are a press fit, the bearings will have an amount of side thrust that ball bearings can't tolerate very long. That is unless you have measuring equipment that reads to 0.0001. If they were that way from the factory the factory' they got lucky and you did too.
If one bearing is a press fit and one a push fit install the press fit bearing first being certain the outer race bottoms in the housing. Install the second bearing being sure you've previously put the spacer sleeve in.
Position the second bearing anywhere in its bore and when the sheave nut or the blade nut ( on some ) is tightened that bearing will find its home in the right place without either bearing having any side thrust at all.