I can't help you with that one, since I am only familiar with my setup. I'd still try and call John Bond and see what he says about it. It might just be an earlier version of the same part; both have the same 96 350 MAF label on them, so that would suggest to me that they served the same function, albeit it redesigned at some point.
And yes, you definitely need it, you'll have much bigger problems like a holed piston if you don't have it.