Start with the fact that most parts are made offshore and many simply don't meet the quality standards of old.
Also check the bearing retainer on the transmission. If it is excessively worn or under-size the bearing may not slide properly.
Another wear area is the release arm. Some wear on the fork could be an issue.
I don't have any knowledge of a specific product known as a "self aligning" release bearing. I believe if all the components are within the wear standards, all bearing would be "self aligning".
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine