Hi,
I tried to post a response to your questions in the 460 forum but couldn't get log'd on for some reason.
I am doing a conversion using a '95 EFI 460/E4OD into a 1990 F150 and was having similar issues to you.
I found the
www.fordfuelinjection.com website pretty helpful. They supply resistors for tricking out the emmisions solenoids/air pumps etc. Doesn't appear to need anything exotic.
The VSS problem can be overcome with a signal interface from Dakota Digital (SGI-5 from memory). Just need to calibrate it based on the pulses from the rear axles ABS sensor.
The E4OD trans would be massive in a Mustang??? but much better than an old C6 you should have stuck with it. You can get a 460 ECU from a manual trans vehicle (lots of the F150/350's had 460 with manual trans) and swap that so you don't have problems with not having a E4OD trans.
I bought a separate trans controller from BEC but thought I would run with the factory setup to start with. The instructions with the BEC unit explain what to do with the computer.
Anyway your project is looking good - have fun
Regards
Chris
Wellington
New Zealand
I am adapting a B&M Quicksilver shifter. One of the levers supplied fits the E4OD with a small amount of filing but the "Park" position will need adjustment.