Well, it turns out that the blazer isn't so super after all! The 1 year old 12-bolt let loose yesterday. Something punched a hole in the cover and it sounds like a tooth on the gear is missing. Richmond 4.10 Gears. I found a couple of 3/4 ton full floating rear ends a the local junk yard and the owner said I could have my pick of the best one!! I found a 14-bolt which I think is a pretty good axle. I also found another heavy duty axle but not sure what it is or what year chevy it came out of. It has 14-bolts and the rear cover is flat except where the ring gear is. CAN ANYONE HELP ME!!! Is there a web site I can go to that will show the different types of rear-ends?