The final price all depends on how much work you can do yourself and how much you pay for the engine/transmission. I bought a 1998 T/A LS1 and transmission for $1600 and came in under $3000 total for the swap. Then again after the conversion was done I started doing more and more to it and now have a 408 with ported heads so I'm really in debt in this thing now! In the conversion section is an OBS to LSx engine topic with some decent reading and hints for doing a conversion. Wiring harness and PCM is a major expense in the conversion, somewhere around $650 for a nice clean and simple to install harness and then you'll need a PCM that the VATS and some of the emissions sensors are turned off.