[Topher]

I have an 04 5.7 and would like to upgrade the power and torque output to pull my freshly acquired car trailer with my 67 Charger on it. I looked through the engine section, and even did a search to no avail. Any and all help is appreciated.

I used my Sir Bourbon to pick up the trailer because my son had my Durango.

Topher

 

[Primus]

You are already putting out 345hp and 375ft-lbs., there really isn't much more you can do that will get you much more than that.
You have the usual power adders that you give you better power but it will get pricey.
Depending on what your gear ratio is, your towing capacity is going to be more than sufficient.