Websites and emails are good...but I always call them to order stuff. They call them Header gaskets. They are copper washers that were made specifically for the NMP header.

You don't want to use something that can eat into the head of the engine, or the header body...If it is not smooth then the copper washers may not seal and the result is it will come loose over time.

Your header must be a fairly old one. You may not be able to put the copper gasket washer inside so you only need the one washer between the head and the header body.

The idea is not to grip but to hold it in tension. See the header is aluminum. The head is aluminum...The copper in between the two parts will expand due to heat differently. I don't know off the top of my head the coefficient of expansion of the copper vs the alum but they are different. The result is washer acts as a gasket and keeps the bushing tight. We came up with the washers about the 2004 NATS. At that time we changed the headers a bit to take a washer inside the header as well. I have only run one of the new style with the washers internally and it works the same. I have 3 in service right now and all of them are the older style. Since you have the older style you are probably not bottoming out the bushing nut....So just stick a single copper washer in there....I think there are 2-3 washers in a bag for like a $1. These were a special size both OD and ID so Central had them produced for just this purpose.


Call Mandi up and she will take care of you...but call early enough on Monday and she will get it taken care of for you.

Troy