about the best you can do mate, is take all the bearings & the linkages to any good engineering business, and ask them to replace all the needle-rollers with phosphor-bronze bushes and machine new linkage pins to suit. They will also need to fit up some new grease-nipple points so you can grease these spots regularly.
There is nothing available *off-the-shelf* to do this conversion on your 750.
I did a similiar conversion on my YZ490 several years ago, the old roller-bearings were all flogged out because in these types of suspension, the movement of the linkages does not allow the needles to *roll* - what happens is that they just *rock* backwards & forwards in one position and eventually flog out.
Phosphor-bronze bushes will provide a heaps better alternative.
