Steve, MattG was able to adjust his Kwik-Way loader with shims to get it to lift more. You would have to contact him for that info as it's not on his site.
This Kwik-Way model can lift 750 lbs. Which happens to be the most of a factory made FEL for cubs. I'm sure CADPlans or PF loaders can lift a lot more but those are more of a custom loader with some assembly required.