what do these heads bolt to??????

i just happened to see these on ebay and was just wondering what kind of short block these would go with just for curiosity's sake lol

[ame="http://www.ebay.com/itm/201205314157?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT"]Complete R5 P7 Mopar Dodge Top End NASCAR Late Model Modified | eBay[/ame]