Lambie said..
Kami is on the money - just use 50lb fishing line or even dental floss and pull it through - if the pulley breaks then it was time to replace that also !
Ronstan blocks work with some kites to replace the pullies - but why?? they still need to slide and wear out the bridal lines even faster ....
Why because the pulleys can eventually fail As you said in your post. The ronstan block don't seem to wear the lines at all from my experience. The friction of the block is probably less than that of a pulley wheel that stopped rolling due to clogging with sand. I have heard of problems of wear from other brands of block due to casting imperfections.
