If your truck isn’t paid off, call the bank and get their blessing. You’ll likely run into issues with your insurance company as the VIN won’t jive with the driveline. Same goes for any warranty, service plans, etc...
One other administrative item... I have a real hard problem justifying swapping an engine/transmission into a vehicle that’s readily available to otherwise purchase. Prime example, swapping a 5.7 into a Ram. You’ll be on your own should anything eff up, and let’s not kid ourselves, things will not go as planned. If you’re going to swap engines, swap in something unique.
With the nanny clerical nonsense out of the way, let’s do this.
This is not a complete parts list, but if you’ve got a clean mechanically sound donor, that mirrors yours you’ve got it made. By this I mean the cab and bed match (i.e. qc/sb, rc/lb, etc..).. 2wd vs 4wd is irrelevant at this point.
Option 1 - If the cab and bed configurations match do a body swap. Assuming like for like bodies and beds, swap yours to the donor. Quick and easy. Minimal to no VIN Frankenstein issues and you’re good.
Option 2 - If the cab / bed do t match you’ll need everything mounted to the frame moved to yours. Pull the front clips to make life easier.
I would need to verify there are no structural differences between the V6 and V8 frames aside from engine / trans mounts. Assuming there are not...
You’ll need to swap the engine and transmission mounts, radiator and related assemblies, engine and trans electrical harnesses, under-hood harnesses, battery tray (larger battery), HVAC system (different orientation), power steering system including the steering rack, full exhaust system, fuel tank and lines, all fluid reservoirs, the PCM and BCM.
Suspension wise, you’ll need the entire front suspension as the V8 is heavier and has a different setup than the V6.
You’ll want to swap the drive shafts and rear end.
I may have forgotten one or two things, but this will get you started.
Have fun as that’s what it’s about after all and keep us posted.