I was checking out ORS the other day, and they still show an expectation of needing about $4700 to do the swap yourself. Yes you can do it w/o their kit, as some have, but its a headache that most wouldn't want to have to go through, especially when you have a problem and have to race it down yourself.

Since you already have headers/intake/ehaust/etc, I would recommend a rebuild of the 3.0. I would have the cyls. bored either .020 or .040 over and run larger pistons. A master rebuild kit from EB runs $298, figure another $500 for the heads to be rebuilt/check out, then figure about $165 for a new knock sensor and knock sensor wire, and another $2-300 for misc. parts like pulleys, tensioners, or anything that might get broken in the tear down process, and the what ever the machine shop charges to bore the block. I would think it should run you about $1500 for the rebuild provoiding the heads are in good shape. You could consider getting the heads ported/polished and enlarging the valves, figure about another $1k, but according to EB there isn't all that much material that can be removed from the heads to really benefit from larger valves.

With an engine hoist or a come-a-long and a good beam you should be able to do all of the work at home, in about 6 days(if you really take your time) not including shop time for the heads and block. I spent about 24hrs tearing mine down, most of the time was used making note of wear everything went, taking pics and video, and keeping it all seperate on the bench, so I wouldn't mix up bolts(I put the bolts in cardboard in the order they came out). I could have done it quicker, but all the work I did tearing it down made the rebuild a snap.