Block and tackle window balances

I would like to replace window balances that are block and tackle. Windows were installed 2002 and otherwise appear in good shape. Vinyl, double hung, tilt out. Balance for upper sash appears same as lower sash. Approximately 6 windows, all same height (60"). I found labels with AAMA certification and work order label but no brand name other than a model 3000DHX4660EI. I couldn't find a manufacturer when googling. No part numbers on balance assembly. It appears that the block and tackle component no longer slides up and down on the fiberglass rod. Profile of the lower part that slides in the window frame track is 1 1/4" by 7/16". Thank you for your help. Charles

Thank you. I watched the conversion video and will order accordingly.