Rick--

Those cars are huge and MEGA ugly, they old Holdens.

A RB30 is a 3litre straight 6 block fitted as std to ancient non-turbo skylines from the early 80s and holden turbos like in the vids.
Using it as a base for an engine using a GTR RB26 head and a fappin massive turbo creates a very special engine, like in the vids.

Articles thatd tell u a bit more
http://www.autospeed.com/cms/A_0042/article.html
http://www.autospeed.com/cms/A_1560/article.html

Here it is in original single cam form (and STILL over 750bhp, lol)
http://www.autospeed.com/cms/A_0485/article.html