Looks to be a bad casting. Two shots of each the new and old pump. The shot looking down through the bolt hole of the old pump (sort of) shows the casting to be thinner on one side of the bolt hole. (Core shift?) That's were the casting crushed. The block, heads and the pump all say, "Mexico" on them, so I guess the pump is original to this crate motor.
http://s978.photobucket.com/user/Pic...%20Pump?sort=3 I couldn't upload to the site. Said they were too big, and I don't have a clue how to compress them.
Thanks for that info, Bill. I, of course, just put it back together today. I used 55#.
Thanks, everyone, for the help.