Go for it, you will never look back!
My first engine swap ever was, a few years ago, to put a 6.0 liter into my '70 Impala, here are some ideas from my experience:
You will have to modify your fuel system, with high pressure electric fuel pump, return line; this means mainly modify your fuel tank with return line. You can use an outside, frame mounted aftermarket pump, mounted as low as the bottom of the tank, it will be easier. Do not forget to use high-pressure rubber hoses/fuel filter...
The new engine is metric hardware, you may have to pull some hairs to connect for instance power steering pump to your old power steering box...
Use a reputable company to have your computer reprogramed and harness modified: I have used a place called Speartech, the owner John was VERY helpful, even with stuff like fuel line... And when I turned the key, the car started first time!
http://speartech.com/The engine/trans harness is easy to install, it can be kept completely separated from the old harness of your truck: no need to worry if your old harness can supply enouhg for the EFI. You just need a few battery plus, ignition plus and grounds...
I have read a lot on LS1tech and asked a lot of questions. Even reading about different swaps, you will learn stuff and be able to use the knowledge you gain.
In the case of my car that came with a 350, I just bought a pair of engine mounts adapters, and I just had to move the trans crossmember a few inches back.
These engines being quite efficient are easy to keep cool, so no need for a giant rad.
Make sure you get your engine with all the accessories on it, accessories from Camaro, Corvette, truck mount differently and you cannot really mix.
Lokar company makes some cool adapters to connect column shifter to trans.
Have fun!
