So I've ruined a few of roller fairleeds for a winch, they use these plastic inserts that can only handle so much. I ended up figuring out size of bearings that can replace plastic. I just did this so I have no clue how it will hold up, but I'm hoping better than before. Here is what I've used if anyone wants to try. Bearings are 5/8 x 1 3/8 is just got some cheap China special bearings https://m.ebay.com/itm/-10-99502H-MOWER-SPINDLE-SEALED-BALL-BEARING-5-8-X-1-3-8-X-433-GO-KART-CART/302295734698?itemId=302295734698&fdback=1
Needs bit of minor modifications to make it work, hoping it will be much better than plastic crap. I put few talk welds to keep bearing from going too far but you can get bearings with retainer rings too so that they only go in so far.
https://m.ebay.com/itm/10-499502H-NR-SNAP-RING-SEALED-BALL-BEARING-5-8-X-1-3-8-X-433-GO-KART-CART/292240544331?hash=item440ae4d24b:g:4CsAAOSwpiNZrfOv