It has been done, but if you're thinking to get it done super cheap then its not gonna happen. Glad you're getting a good deal on the LS1, but expect to spend at least another 2-3k doing the right engine harness, engine mounts, etc. Then you get into the possibility of needing different driveshafts if you move the trans (so keep it in the same place). Oh, and a stronger trans and different rear end to hold the power. You could do the engine swap and leave everything else, but be warned you're going to need a rear end and trans pretty quickly. There are some guys on here and OffroadTB that blow the 8" rear end up with an I6, GM should have just given all of us the 8.6" and kept the 9.5" for the SS/Aero.