JD
I know the front axle is freakin' heavy. Thats more than a dana 60 in a Chevy 1 ton, which is just heavy.
I found this on E bay. It lists the shipping weight of a 251 and tranny at 700-800 lbs.
http://cgi.ebay.com/ebaymotors/ws/eB...category=34202
Hope it helps
Randy