When FoMoCo was exploring the use of the 4.6 in the LS, they contracted McLaren to build a couple of prototypes. And mostly because they were available, McLaren used five litre variants, made possible by the use of the Nikasil process on the cylinder walls.
Everything could be made to fit from both side-to-side and fore-and-aft perspectives. But they discovered that they either had to go to a dry sump system to gain space to lower the engine, or, alternatively, use a lower profile intake manifold. It was simplest to cast a new, lower profile, intake, and they did so from magnesium. The available flow was the same as the composite production piece, and allowed the five litre engine to make 480 HP and still fit under the production hood with no needed alterations.
A quick look through almost current threads in the regular LS part of the forum will show a project of installing a 302 engine that is currently going forward.
KS