Many of the rod suppliers (Speedway etc) have kits for these......you would be much further ahead than trying to adapt something that isnt made for that application........I hate the idea of kits for everything too, but this is one area where I would do it.
The reason I know that is, when I was younger and stupider, I had the bright idea of putting power window in my el Camino from a 66 Impala...............Talk about a nightmare. Did get it done, but they never did work well.
only drawback to aftermarket kit is most of them are generic at best. most of them look like they have gm cable style motor with modified drawer mechanisms. hit the pull-a-part and check out some setups. seemed like the rear door motors always were in better shape. good luck.