I've heard both sides about Toy birfs VS. Dana44. What I can tell is the Yukon kits inner and out are larger OD then a stock dana44. The inner shafts are the same size as the OD of the splines. Our Marshafts are the same way(they also have no inner C-clip for the birf to bottum out on, the shaft has a shoulder so its not any smaller at the weakest point). A stock Toy inner shaft is small then the spline OD. The Yukon outer is also larger( shaft and spline ) then a dana44. The outer is the same size as a Toy birf. I know once I install the Kit (still unsure of what 3rd member combo I want) I can always change it back. I just need to carry a birf,inner and outer shaft, and a stock spindle ( same stuff I always carry ) for trail spares. Most importantly is my front end will never have to make "Birfield Soup" again. That not to say it won't leak, the long side will always leak but the bronzs bushing will slow the flow and support the shaft from bounceing on the seal, and there will only be the grease on the lower Knuckle bearing to make soup with. I hope to have a new years day run test.
