yes it is a type s flange.
you need to take your 1g bov pipe to a machine shop and have them cut and weld the new greddy flange on.
it doesnt benifit any if its steel or aluminum, no benifits from either. i believe it depends on what type of metal you plan on welding the flange to. id go with aluminum, thats just me.
oh and it doesnt go onto your "intake" pipe as you call it. a bov is bolted onto part of your uicp (upper intercooler piping)

Oh snap, my bad haha. Long day at work

You don't need the flange. http://herpetology.com/dsm/bov.html

Wow thanks oldman. Forget buying a flange i'm going to try this..I really appreciate it!!

-See you on the 22nd?

No problem Shlomi, make sure you recirculate that BOV and boost leak test.

Always do

If you don't want to drill holes in your 1G flange, www.dejonpowerhouse.com makes an adapter to bolt a Greddy bov on a 1G flange.

Thanks, that's what i've been looking for from the begining