Same year 4.7l v8 compared to a 3.7, you'd gain 20hp and 60ft lbs of torque... plus a small amount of weight (I could find a weight for the 4.7l engine, but not the 3.7l- 438lbs).
So the extra torque would probably be noticeable, especially from a stop or slow roll.. but is it really worth all the money and hassle? I don't think so. It's cool.. but not very practical.
More impressive to me would be swapping in a newer Pentastar v6, either 3.6l or 3.9l. Either one has between 280-305hp and gobs of torque, much smoother and reliable operation. That would be a crazy difficult swap too, but probably actually worth it.