well, tonight i was doing some surfing on LS1tech and randomly came across a thread about how some 01 & 02 f bodies supposedly got a true LS6 block instead of the '168 ls1 block. They were going back and forth about what are the real differences. so all that got me thinking, did they really do that and how could you tell. I searched the web for the answer. First off most people said theres a "bulls-eye" casting on the passenger side of the block in front of the head ONLY on LS1 blocks, and nothign on LS6(but some people say a few ls1s didnt have it either), then some say the "coloring" of the block, and then the LS6 blocks had the bay-to-bay "windows under the cylinders, thats the best way to determine it, so with all that going around in my head, i couldnt resist to look at some pics i took of my old block, when i disassembled it and right before i took it the the metal recycler for scrap value. Well, low and behold, it was a true LS6 block that was originally in my SS...
oh well, life goes on, but i guess i now know for sure that GM did use the LS6 blocks in the f bodies..