I have a 1999 Tahoe 4 door 4wd as my daily driver. Had a friend look it over the other day and I need to replace the lower balljoints. He told me to get the parts and he'd put them on. Well I called my local Spicer dealer and they offer two ball joints for my application.. One is a 46mm and the other is 48mm. My friend wasn't sure without looking at them... Anyone know a way to determine whcih one without buying them both an see when my friend gets into the work? Thanks!