Ford triton engine rebuild question

[trlcavscout]

A question for any one working at a ford dealer or that has had a triton replaced recently. I am trying to find out a ball park cost to do a long block on my 2004 F150 with 5.4 triton. it's a nice super crew 4 door cab FX4 and everything is in good shape except that awesome engine that knocks. I bought it used and i am still paying on it but I am afraid to drive it very far so I am trying to decide if I should spend the money on replacing the engine or just park it out back until it's paid off and sell it for parts. It runs good and has no loss of power or check engine light but it makes a lot of noise.