I just want to add this....
BUY THE FORD SERVICE CD AND FOLLOW THE DIRECTIONS EXACTLY.
This was my first entire tear down and rebuild (minus taking apart the heads). I had done a few top-end and front end rebuilds on older RWD cars but this was my first time building a whole engine (minus heads).
I followed the directions on the ford cd and my 3L has been running fine for the last year. And for those of you thinking you can't build it in a hurry when you refer to the cd, it took me 2 days (about 4hrs a day) to pull the engine. I had already prepped and had the lower end all ready for the svt parts. It took 2 days (about 3 hours a day) to swap everything and get everything PROPERLY TORQUED, then I had to wait 2 weeks for my new water pump and DMD, then about 6 hours to drop in the engine and secure it and hook everything up, then the last day I took about 3 hours to install the axles and hook those up and make sure everything was connected, and fill with fluids.
That really isn't a lot of labor time for a first time rebuild.
And to all the people asking a billion questions about the swap, ALL the information in performing the swap was found in the old forums (they were old a year ago, but ya know what I mean). I belive I made 2 posts regarding little problems I ran into, 1 being advice on getting out the damper bolt on the 3L. All the info is here. I know this because its what I used. Take a couple hours for a few days and read the old posts, try searching more than "3L swap" or anything else thats vague. Try searching using more than 1 or 2 specific words. All the info is there.
But as I originally said, if you follow the directions on the CD, and assuming there was nothing broken or wrong with the engine in the first place, you should have no worries.