the ford 660 is the biggest engine i could find and it should fit cause its a suped up 460 and with a little work like mounts and maybe some rearanging it should fit in the engine bay here's the site http://www.crateengine.net/
What about the rest of the problems created by putting that engine in there? You guys read a question, google what you "think" is an answer then post it. Sadly, often an unsuspecting person heeds that stupidity you've posted. Unless you've actually done the procedure or know first hand of the installation, materials needs, required fabrication and unexpected contingencies....KEEP YOUR BAD INFORMATION TO YOURSELF! You'll get some one hurt or killed and best case, cost them some money.
Search Ford F-150 Questions
Ford F-150 Experts
Related Models For Sale
Used Cars For Sale