Congrats jlbota,
I just got one too! Mine is a 6spd HO DRW 4x4. I really like this thing so far. Had mine a month today. A couple of good sites that discuss these trucks are
Diesel truck resource and
Turbo diesel register forums.
I looked at the bigger trucks and if I wasn't going off road that would have been the way to go money wise. The Dodge was a good compromise for us. will pull the trailers and work in the pasture.
Swapping engines in chevies, is not too big a deal. We did a pickup from a straight six to a small block. Had different motor stands, but they just bolt in place of the others, same crossmember for transmission. Went from a powerglide to TH400. Fan shroud was changed also. different yoke on driveshaft for new transmission and speedometer gears. If you plan to keep the burb you can drive the money's worth out of it. I had a $2,500 truck put $2,500 into it drove it another 80,000 miles and could still get $1,500 to $2,000 for it. So the 80,000 miles cost me 3-$4000. Not bad considering what a new one costs.
Reason for buying a new one was bigger family and 4wd.
As far as insurance goes, my dad wrecked an older car and was offered a low ball settlement. Dad's car was 12yrs old but was extremely clean for its age. When they totaled it, he said fine, I will go find a car in similiar condition and you can purchase it for me. Well, Dad found a similiar car, but had more miles and fewer options than his. All of a sudden his car wasn't totaled and would be repaired.
Not all 12 year old cars are the same. So if you have major improvements to your vehicle keep receipts. It will help establish that your vehicle is not in the typical condition for that age and type of vehicle. A friend had just replaced the engine in her car and totaled it. She was given a higher settlement because of the increased value. She still didn't come out ahead, but recovered some. If you are happy with the truck otherwise, a new engine might not be a bad deal.
If you just don't want to work on it, I understand that too, been there.