Is this what you are talking about?
http://www.ebay.com/itm/04-Corvette-...tWmV9d&vxp=mtr
http://www.ebay.com/itm/01-C5-Corvet...9W2cAG&vxp=mtr
There are a couple venders that usually have them on ebay. Price depends on year and engine, but it seems like the LS1 stuff is down to around $6k-$7k. I think it's a good deal if you want to build something with a c5 suspension and trans axle.