I would go with the 4.6 and 5 speed. Put a carb setup on it to make it easier to work on and easier on the wallet. Later you could do a blow through supercharger on it! My engine builder has a mustang with a similar setup and is knocking at 700 horsepower with only 10 lbs. of boost!
A friend f mine in our Mustang club just finished a 14 month project on a '67 Stang fastback using a 4.6 out of an '06 police car. He did the Mustang II suspension, cutting the shock towers out completely. It looks AWESOME!!! Much better than if he had used a 302 instead. I vote for the 4.6. Jim
the price is right on the 4.6 mustang so why not, they make decent power, for a light maverick, they aren't a heavy engine as well, and there are quite a few performance parts out there for them , and you already have the mustang II front end to help the swap along. it don't have to be race car fast,to be cool and could be made to run fast enough to hold its own on the street, and if you wanted race car fast(to me :9.90 or quicker) you wouldn't be running a small iron stroker or a mod motor, it would be a big sbf stroker or big engine ,and likely not to drive it on the street . I had a 2004 gt and a 2007 gt mustang and the mod motors were fun, and could be set up to run good and they are a good looking power plant, well enough from me I wish you luck either way it will be cool and isnt that what its all about.....
This car is mainly going to be a driver, show car. It may see the strip once in a while. So Im really not building a drag strip warrior. If the car runs low 13's I'll be happy. Im waiting for our 1st time home buyer tax credit to get back. I get to spend at least 3 grand on the Mav!