Only the ZR1(LS9) and Z06(LS7) have fancy internals. The rest have hyper-eutectic pistons with cast crank and rods. Six bolt mains are on all LSx engines as well. The bottom ends are pretty dang strong. Most people go ahead and do rods on an expensive build but 6-700 hp on a stock bottom end with just a piston change is durable and often done as well.
Did a quick search and found exactly what is in the engine here
http://www.crateenginedepot.com/prod...roduct_ID=1821