It sounds like a fun project. I would suspect that you first have to determine "WHY". Are you looking for more horsepower for straight lines, a more powerful engine while retaining handling, A fun project, or ?????
A good starting point is considering the engine weight so that you don't mess up handling and braking; engine/transmission dimensions so that it will fit and can be worked on without problems getting into narrow spaces or having to rebuild the trans tunnel for fitment, and final torque/hp anticipated to see if the rest of the drive train is up to the tasks. Then questions like 'can it pass smog, can it be insured, can it ever be sold'?
The engine weights can be approximated by internet sites such as http://www.angelfire.com/ar/dw42/engfyi.htm
. A personal favorite engine that I drove back in the 60s was the Olds/Buick/Rover Aluminum V8 - 318 lb engine, 215 to 300 ci depending on which rods you use, and at the time put out 1 hp/ci in the turbocharged version. (Distributor in front, too
. The D&D link has complete remanufactured engines all the way out to 5 liters! (GM sold the tooling to Rover, so newer blocks come from overseas and cost a lot, I understand.
The Ford engine would have the advantage in that it has already been done, and there are lots of heartaches that can be avoided by being the 2nd or 3rd person to invent the wheel, such as knowing in advance what won't work, a list of problems and fixes, etc.
Good luck, and post pics!