mopar ebay engines?

found a few different people selling custom built BB mopar engines on ebay. Wondering if it is anyone on this site? One of them is called blue monkey and here is a link to another one..
512 440 STROKER ENGINE 625+ HP MOPAR MOTOR COMPLETE PRE-RAN TESTED AND TUNED | eBay

I would like to have that 512! But then i couldnt say i built it myself anymore though..