[Mike C]

Unless some previous owner took it off and tossed it, there should be a metal tag on the front diff underneath two of the cover bolts showing what the front ratio is. Usually it is covered in grease, so spray around the cover with carb cleaner and a brush. If it is missing, this would be a good opportunity to change the fluid in the front. Was the rear rebuilt or was the ratio changed? Either way, I would want to know for sure. I have a K30 with a Dana 60 front that the tag is gone off of. The front driveshaft was out when I got the truck, and someone has drawn a line through the 3.73 on the SPID and written in 4.10. All of these things are red flags to me, so both covers are going to have to come off to figure out exactly what some PO has jacked with.