Truck engine replacement

I have a 2006 ford f150 with the non-flex fuel 5.4 recently it stopped running and when I took it in to 2 shops for diagnostic they stated #8 cylinder had come apart and I needed a new motor. My question is this. What is the cheapest way to do this. I found a motor from a navigator with 89k miles on it for 2300. How much should I expect to pay to have it installed. And is it a good idea to go with a motor like this. I only have about $3,300 to spend and from everything I read this is no way enough. What can I do I need to get it fixed