I can't believe I'm about to ask the question that I've considered so dumb for so long. People are always asking "Do I need a new tune" and the answer is almost always yes. I'm in a bit of an odd situation though. I have an AES built 390ci LQ9 stroker short block that I've transferred my LS1 top end to. Parts are in my sig. It still has stock injectors and fuel pump. Everything is the same as before except for 44 more cubes and a little lower compression ratio. I know I don't have to worry about initial startup because the injectors/cam/heads are all in the tune already. My question is can I safely drive this thing ~5 miles from the shop I'm using to my house? I've never seen this question asked before.

 

You'll have to baby it, since I might not be used to the extra displacement. The o2's will immediately notice that there's a lot more air than normal, so they'll help a little bit, but I still wouldn't use more than 10% throttle taking it to the shop. But since it's only a five mile drive, I think you'll be okay.