Yeah, Rat motors are usually refered to as built up BBC's (Big Block Chevy's). There is also a term "Mountain Motor" and that is usually 520+cubes all the way up to almost 800CI which is about the largest BBC V8 that can be built.
Not sure if you are to familiar with other engine terms but here a few that you should know.
Short block = Block,crank, rods and pistons (or the rotating assembly)
Long block = Block,crank,pistons,rods,cam,push rods,and heads and intake.
Fully assembled long block= all of the above and usually comes with carb and all the brakets as well as fuel pump and water pump and starter and alternator
There are alot more out there but I can't think of them now.
93 GMC Yukon
Chevy SuperStock 4x4 Truck Puller
Great Lakes Truck & Tractor Pulling Association