I have a Ford 7000 that had water in the engine oil. I thought it was going to be a bad head gasket but when I took the head off the gasket looked good. Then I noticed a pinhole rust spot in one of the freeze plugs in the head. I took the head to an engine machine shop and told them to make the head right, replace anything that looked suspicious. They said the valves and seats looked good and only replaced the freeze plugs. Cost= $35.
I also have a JD 310G. I have found so many uses for that machine at the ranch I use it almost every week. In the last two weeks I have used it to clear off an old fence, fill in some pot-holes in a road, dump some rip-rap in a ditch that was washing out, dig out some mesquite stumps around a tank (pond to you northerners) put some bull-rock in the spill-way for that tank, and am now digging a ditch between my shop and a shed so I can run some power, water and air lines to the shed. Also used it to drag some pipe out of a field for that project.
I am sure you will find many uses for your 480.