The '04-05 are no better. The '08 is where the big change was made in the 4.7. I can't imagine dropping a Ford or Chevy engine will be cheaper considering you'll have to swap transmissions and have drive shaft work done at the very least.
from looking at reman engines it looks like there is going to be something different for 08 for a direct fit, there listing it showing 2003-2007 Dodge Ram 1500 with the 32 points on trigger wheel.i mite be missing something, so if someone else want's to chime in.
also looking at remans i found them for
List Price: $2,695.06 Our Price: $2,283.95 You Save: $411.11
Core Price: $427.00 http://www.thepartsbin.com/catalog/?...486+4294962021