I'm not sure on the serial # right now. We picked up the parts today. It's all metal. There's metal tubes that have some sort of rubber gasket in them that slip over the injectors where the T's went. Then the T screws on that, and then there are 5 pieces of line that I think screws on between all the metal T's. I didn't look at it closely yet, Dad got back with it when I was about to go home this evening. Parts guy said he didn't think there was any around that had the rubber T's anymore. I looked at our 4440 and it's got the rubber T's on it too still. I think the metal parts will be easier to replace since it's all in pieces. The Rubber T's are on one line that runs from front to back. I think the only way to get it back in would be to take all the injector lines loose. I don't know how dad got it out without bending the line. At first, we thought the line was in pieces held together with the clamps.