Actually its a Knock-off, We (me and my welder) had a shitty SS laying around, that just so happend to have a nice crack in the collector, and we used it for a mock up, Its the same specs as the SS but welded and fab'ed 20 time s better, and it was all hand ported for better flow, cost me $250, took him about a week to get it just right.. I have alot of people comment on my manifold, I would never go as cheap as putting one of those mani's on my setup. I tell you what tho, I have heard they flow pretty well, just pron to cracking. Oh well, you get what you pay for, Thanks all for the comments..