Stored for years in an old line Honda Dealer. It was marked 183-320-677. The Honda iden tification guide shows the K4 as a code 320 which is shared with the 1970 K3 model. This muffler is in beautiful condition. Some areas of light surface rust, mostly in the rear, but absolutely solid and no rust through anywhere. Please make sure that this part is correct for your application as there is no return of parts. Check out the pictures, you will really like this exhaust. I can take more pictures if needed.