The only national sanction body that requires billet wheels is USLMRA and that is at a national points race. Their rules for local levels are different as well as the US Open type events to allow other racers to compete!
So Justin, I remember the rules being at least 1/8 inch thick steel. Then there was also a 1/4 thick by 1 inch wide 'strap' across the top of the shroud. Basically its a 'free lance' design as there is nothing off the shelf so there's no right or wrong way to do it. My opinion, stuff it underneath the shroud. No, not so its 'hidden,' but if built under the shroud then it can be kept as close to the flywheel as possible. The less room between the flywheel and the scattershield, the less of a 'run' the flywheel pieces would have towards the shield. As we all know, the more room to gain momentum, the harder the impact. Beeping the scatter shield close would help. Basically the only way I can figure to do this on an intek is leave it probably a 3/8-1/2 inch off the flywheel in all directions then once you get up to the coils, go out and around them. Let's face it, if its gonna break, its smashing the coils anyways! Then when you have the shield itself done, find a good spot on the block to mount it to. Not the bolts that hold the factory shroud on. I would say that you could probably weld some tabs on the front and get them down to the intake bolts. Those are probably the strongest point at the front part of the motor...as for the rear, hmmm I don't recall much to great back there. I would be willing to say though that you could weld some 18 gauge or something to the sheetmetal that goes under the flywheel to get a thick enough piece to bolt to. Just do it strategically. Then 2 tabs off the backside of the scattershield to hold it to the block. Then drill and tap the pieces into the sheetmetal you just welded to that bolts to the back of the motor. I hope this makes sense. If not, ask away and ill clear it up.