As others have said, you have adequate access to the wheel boxes by removing the dash top. While you’re at it, it makes sense to at least inspect the wiper rack and motor. I replaced the rack, cleaned out the dried up grease, and applied fresh grease in the tubes and motor gears. Much better than before on my likely original to 1985 setup. I used the Development Design Eng wheel boxes. I believe JimC has used them as well and reported that they are of superior quality to original parts.