No LRE trucks were W2's. They wanted to do it but something about california emissions... To make sure it's a 360 block, the numbers are stamped on the driver's side front of the block just below the deck.
I remember a shop that was sonic checking 318 blocks and boring them to 4". Strokers were coming out at 402 inches. Or just get that 360 and build a 408-426" small block. That'd be my advice.