Here is an example of where the green bearings solve a problem and should work on pontoons. Found a set in the parts that came with it which were larger so maybe someone thought the same.
The early 8 3/4 used shims to extend the retainer outward with a foam sealing gasket. Removing shims reduced end play. Later they added an adjuster to one side to take up the slack. Tucker didn’t have this so started with tucker tolerance.
All the 8 3/4” cats I have had apart they are all recessed with lots of end play. My guess is it’s from years of slopping around.
My solution was to have these shims made up solve the problem.
Axle play on the pontoon cats should move the sprocket and pontoon together. With the rubber track the carrier is fixed so the sprocket can move side to side hitting the carrier which you can see in the pictures.
These didn’t have foam seals. Diagrams don’t show but can’t hurt.