exhaust manifold

[smithw44]

So finally got motor back into the 76 440 cyclone after a good cleaning and new crank seals and new exhaust manifold. Onto the next problem fired it up and sounds like im running a open header exhaust pipe isnt fully seating on the new manifold. the part number is am54712 i bought it off ebay here is a image of it http://www.ebay.com/itm/NOS-JOHN-DEERE- ... f9&vxp=mtr

it is different from the manifold that was on it where the pipes seat together the one that came on sled had a bigger head on it but was getting worn down and was cracked and the flange for the springs to hook on was free floating this new one has welded tabs to hook springs to. in order to get this one to seat properly you need to undo the 2 big springs that hold exhuast to the bracket on the muffler and kick it in as far as you can but then of course cant put the outlet through the hole in bottom of sled or put springs on so kinda thinking this is the manifold for this sled?