I have an 85 GMC Jimmy that the rearend has gone out. I would like to know if the stock gear ratio is the 3.73 or 4.11, or did it vary. Thanks

There should be a tag on the rear differential cover or it might be stamped on the cover itself. That should tell you what the ratio is. If not, you could try calling a dealer with the VIN #; they might still have it on file.