I wouldn't say their not worth looking at, matters on what you're looking to do. You can make more power per dollar with a FI application. You can look at some 3V 4.6L NA build threads for comparison and see what you think (They will have better gains with the larger displacement ). From what I've read most of them have went the FI route. If you have cash burning you need to get rid of and want to be unique, NA beast it! But when the Procharged, stock internals 3.7 trains you, don't be suprised!
Or you can build it up NA and then add FI and make more tweaks from the NA config to help support the FI too. Don't have to put FI on an engine that just has bolt-ons.