I erred, you would have to open the cases and change the drive side bearing to use the thrust collar type bearing.
The thrust collar goes on the drive side bearing. You have the NF type which has the rollers contained in the inner race and the outer race has a single lip to keep the rollers off the case bore.
The NUP as a separate inner race lip that captures the rollers on both sides, taking care of the crank float.
Another arrangement is the NH type which has a separate thrust collar. This would require the distance piece between the bearing and sprocket be narrowed to accommodate it.
Needle bearings do not like angular misalignment. The flexing of the crank makes the shaft rotate in roughly a cone shape so the rollers next to the crank web are loaded and the rollers 180 degrees around are loaded near the pump end. This causes the outer race to walk. Without something to retain the race in the case to will likely move. The triple's drive and timing side rollers are retained by retaining rings in the cases. They do not have nearly the angular misalignment of the twin with only two bearings holding the crank.