New LS1 Owners - Newbie Tech - Need help identifying engines

Sorry for the complete newb question. But I am planning on an LS swap into my 1969 corvette. Im heading to the salvage yards and was wondering what are the best ways to determine what engines im looking at? Im mainly expecting to find LQ4s, LQ9s and possibly LS1s.

Any help would be greatly appreciated

Thanks
n100

LS1 is gonna be aluminum. LQ4/9 engines are iron.

Right, but are there any identifying markings to distinguish an LQ4 from LQ9? Without pulling the heads?

On the back of the block, gm casted the liter #. 4.8/5.3, 5.7, 6.0...
http://mycarpics.shutterfly.com/183
As far as the lq9 to lq4 you'll have to see the serial # of the blocks.

yea i think the serial number is gonna be the key without diving into the engine

very cool, alright liter on back of the block. Thanks guys

n100