just want another opinion on it but do you guys think this is a good deal? im not sure how much a reman. engine would be. but here is the link to the craigslist ad with the pics and most of the details.
2006 Ford 4.6 L Police Intercepter Engine
No, I wouldn't use that. Engines from police and taxi service vehicles are a particular no-no due to severe duty use - idling for hours on end and generally very high mileage (often 300K plus).
Considering a "clean" engine typically goes for about as much as that guy's asking (and that's toward the high end, I've seen decent engines as low as $800), a more honest price for that slug would be like maayyybe $400.
**EDIT: Sorry, I did not notice you mentioned "Police Interceptor" in your first post or I woulda poo-poo'd it earlier. I see it's advertised as having 62K, which I suppose is possible considering that maybe it came from a wrecked cruiser. If you are really interested in the engine and/or feel you have exhausted all other options then I would do two things....
1) Attempt to verify the mileage of the engine. This can be done if the current owner of the engine has and is willing to supply you with the VIN information of the donor car. Then, just spend $20 on a Carfax report; any time a vehicle is wrecked, retired, registered, changes ownership etc it is reported to DMV which is where Carfax gets the bulk of their info from.
2) If all checks out, try to talk him down. I'm thinkin' $800 is fair and shouldn't be busting his balls. If he paid more than that then that's his bad - we all take losses in this life. Use the reasoning I mentioned earlier about it being sourced from a police service vehicle and the "ridden hard and put away wet" severe duty blah blah blah.
If you are unable to accomplish one or both of those things, then I hope you're good at gambling. It could honestly go either way - best engine you ever had or a complete turd from the get-go.