Since it's been proven that a Crown Vic *can* tow 5000 lbs with a stock 4.6L just fine WTF is the logic behind going with a 10+ year old B-body instead?
Every single B-body I see on the road lately--and they're not many of them in these parts that are still road worthy--looks like it has been beaten hard and put away wet repeatedly every day of its life. The remaining Impala SSs especially look like freaking beaters now.
These days, I'd personally be really
hesitant to pick up a used B-body as a tow vehicle, especially considering that Ford is still making the Crown Vic a decade later.