[Gregski]

I strongly suggest you connect your MIL (ie check engine light) prior to your first fire up post LS Swap and hook up a code reader, the PCM is able to tell you the errors so might as well go look for them, of course fingers crossed you're hoping not to see any, but if you do, some may be a quick resolve, such as the P0418 Secondaery Air Injection System Control A Circuit