Besides Project Reaper, I have a 2001 4wd Dakota Sport with a 4.7 as my daily. I have owned it for almost 4 years and it has been very reliable. The largest repair I have had to do was a radiator and a rusted brake line.
That changed a few weeks ago.
Now it’s pushing coolant into the overflow tank due to a head gasket leak. So far i have been able to keep it topped off and it hasn’t overheated or blown much coolant. With the 4.7 engines, you absolutely can not overheat them or they will drop a valve seat, hang a valve open and smack a piston. Instead of spending $1,500 on reman heads, gaskets and timing set. I decided to just drop a used engine in the truck. I found a 110,000 mile engine from a wrecked 2001 Durango for $500. Score!
So I brought it home and discovered a leaking freeze plug behind the flexplate. At 110,000 miles this might seem like a bad sign, however when Project Reaper was still a V6/5 speed truck with 60,000 miles on it, it too had a leaking freeze plug behind the flywheel. So I have replaced all the freeze plugs in the block, the oil pan/gasket, water pump, thermostat and housing, valve cover gaskets, intake gaskets, rear main seal and a few other items. One major item to replace when it was out was the crank sensor. It had to be busted out in pieces and popped out from inside.
The only other item is drilling and removing a broken exhaust manifold bolt. Pretty impressive that with four broken manifold bolts, only one of them didn’t spin right out.