I hear you Fallon... And I do wonder which end of the tractor will actually lift more, the loader or the 3pt. My 3pt is rated at 3,000 at the eyes and 2,425 at 24" behind the eyes. My loader is rated at 3,727 break out (pins) and 2,761 full lift (pins). But the loader loses lift faster as you get away from the pins because it doesn't have the linkage that a 3pt system has. So it will be interesting to find out.
Even if it's the same or slightly less, I want the forks on the back for transporting logs about 1,000 feet from my neighbors lot to my wood pile. 1,000 feet on rough terrain is too far to have a 2,000+ pound log bouncing around on the front axle - IMHO. some of the logs are walnut and we're trying to keep them as long as possible - which translates to quite heavy. And it's easy to cheat a load up in the rear just by lifting the front of the tractor with the loader and letting it back down once the 3pt is up.
Agri Supply actually has a nice looking set of 3pt forks for about $200 ($300 with shipping). They are rated at 2,000 pounds and some reviewers seem to be carrying a lot more than that without an issue. But they are still just square tubing rather than heat treated solid forks. And I figure if I'm backing them under a log and digging them into the ground all the weight might be on the tips. Then if I get a hydraulic top link that is a little on the strong side can curl them up... well, maybe they would last but maybe not.
Another company makes a tubular 3,000 pound 3pt fork for around $600 which is way to pricy for that.
To get adjustable heat treated forks, everything I've found is north of $800 before shipping.
Anyway, I think the adaptor with the 4,000 pound forks will work well, especially once I get a hydraulic top link set up.