I dont know whats up with that ad but make sure you get a wideblock, which is 13.25" lower bellhousing bolt tobolt. My truck came with a 2.6 with auto and i can assure you it was a wideblock 13.25" wide, same as the manual trannys. Doesnt make much sense to have a completely different block just for auto and standard tranny.

EDIT: And most of that wide/narrow block stuff you are reading about is people talking about the 2.0 g63b