I thought it looked a little narrow. You did a great job on the cover plate. That's awesome. Looks totally factory. Any particular reason why you decided to cut a chunk out of the middle like that? How did you get the runners to seal all the way around inside? I don't know how you could weld them fully.
You don't need to have a perfect seal between the runners. The intake only moves air and all the runners pull from a shared plenum. I also had both parts planed smooth so leakage would be minimal. Air is always going to take the path of least resistance.
As for why, part is I could and I was going to be doing work inside anyways. It's usually only done with the stock HO and Cobra intakes as they fit back together better. It shifts power up the rpm range 200 rpm but allows the engine to pull farther before dying off. Also gets a little more flow out of it.
Here you can see the bottom doesn't line up quite as nice.
I also opened up the inlet up to 90mm. Its a little overkill but go big or go home. I think I might be the only one to go that big or at least posted about it on the internet.
I like to tinker with stuff and this has been kind of an experiment.