Here's a complete EFI sytem for a 351 Windsor
Ford 351 Windsor Genuine Fuel Injection KIT EFI LOW Intake Manifold Mustang | eBay
I'm planing on putting a 1995 351W in my Pace kit, so far have the short engine. I've been told that it needs a stock cam, heads, cats and a good tune to pass emissions testing. I will have to ask my engineer if an after market EFI systems will pass.