Ok....these headers where suppose to fit a 1991 Chevy Suburban 5.7 1500, 700R4 2wd, but theirs issues here... I called Thorley before hand, talked to Nick and verified that the 367Y3-C (ceramic coated), was the correct part number for this truck, then ordered them from Summit. The 376Y3-C is for burbs/blazers/trucks without AIR injection and without heat riser (the butterfly flap on the passenger side exhaust). Some of these pictures are a bit out of focus...sorry for that. I use this camera for distance pictures....so a 135MM lens really sucks for close up pictures and is a real pain in the arse to focus on something thats 2 feet away. So....here we gooooo.... First issue...a heat riser came with it. Hmmmmmm...not suppose to come with one. Next issue, the oval port gaskets provided for stock port heads? Eh? Shouldn't these be square port gaskets or at least D-port gaskets? Slider piece that slides into the y-pipe alone does not clear the transmission dust shield (inspection cover). 2 of the 3 bolts holes on the driver's side collector don't line up the the holes on the y-pipe. The y-pipe needs to be rotated a 1/4" clockwise, but can't cause it is already hitting the dust shield. The piece that slides into the cat, is 6" too short. The cat is in the factory position as the truck had the factory cat when I got it. I replaced it with a high flow unit...the factory y-pipe was left intact. Ok, this can be an easy fix as well, just have a muffler shop make me a longer one. Last issue...end of collector on y-pipe collector does not clear heat shield flange between the flange and the transmission. Ok, this was an easy fix, just cut the heat shield flange off, but the instructions mention nothing of the sort. Well...I know I'm getting old, but does anyone else think Thorley messed this order up? The y-pipe doesn't fit right....it's too short, hits the dust shield, hits the heat shield flange and 2 of the 3 driver's side collector bolt holes don't line up. The heat riser seems like a big ticket that this order has been foo-barred. The headers fit great....the y-pipe doesn't. This doesn't seem like a direct fit as advertised to me.