It depends on how much work you want to do. The Dodge engine is already mounted with exhaust and power steering, cooling. You will start from scratch with the 5.3. I almost bought a low miles AWD explorter 5.0. I would be driving it now if I did, but for me I wanted to enjoy the build and make it how I want it so it created a ton more work but I have no regrets. Are you doing this because you enjoy the building process or do you want a faster finished product?
My brother is a mechanic and he has had a v8 Dakota for years, I'll text him and see what he thinks of the motor if you want.