Ed, I was thinking the exact same thing when I read jmoore's last post. I haven't had the truck delivered yet because the old tires are rotted and the new ones that I ordered haven't arrived yet. I am going to pay a visit to the truck during the week and will get the casting numbers.
I looked at some pictures that I took under the truck and the rear end might not be original. It has shock mounts welded to bottom of both sides of the axle (no shocks, though) which makes me think that it might be a later model. I'm pretty sure that if it was original, the lower shock mounts would have been separate brackets attached to the spring ubolts under the axle bracket.
I will get the casting numbers. I also plan to jack it up to see if it is an open or limited slip differential and I'll estimate the ratio by counting the tire/driveshaft revolutions.
Matt
