Re: the torsion bars, I don't think it makes a bit of difference with engine in or out.
I just pulled mine the other day, with engine in, and don't recall any clearance issues.
Only tip is to make sure you have ALL the tension off the adjuster bolts on the LCAs. If they've never been removed, be prepared to struggle with them a bit, but once they break free they'll just slide right out.
Edit: Oh... and obviously you need to have all load off the LCAs, ie the front needs to be in the air.