Here's the link for the 292 crate engines:

http://www.usdieselparts.com/category.cfm?Category=1400&CFID=818845&CFTOKEN=780

And here's another one:

http://www.gmplace.com/engine/gmcgmplacegmc_292lb_6.html

Looks like the prices vary. But for about a grand, that's a nice deal.

52 GMC 3/4 ton pickup
68 Big Block Vette
68 455 Firebird