Between from 1969 to mid 1971, all 240Z cars in US came with this type of muffler.
1. Long muffler tip as shown in 1969 Datsun/Nissan Catalog This tip comes over the rear bumper.
Seamless pipe with no steps. This tip was later used on 260Z.
2. Welding seam at the bottom with no name
3. No lock-up bolt & nut at inlet side
4. Comes without paint (Ones sold through parts department came in black shown in photos here, preventing it from corrosion.
Now, as soon as 240Z hit the US market, under DOT regulation, Muffler end had to be shortened.
So most 1972-73 cars came with this type of muffler.
1. Shorter muffler tip that does not stick out over rear bumper. There is welding seam and step at the bottom.
2. Welding seam is changed to left side instead of bottom. Name of the maker "Nichira" and Nissan part # at the bottom.
3. Lock-up bolt & nut welded at inlet side
4. Comes without paint (Ones sold through parts department came in black shown in photos here, preventing it from corrosion.
Finally, let's compare them side by side.
After few years of research and consideration, we came up with the reproduction muffler here!
Reproduction muffler for Datsun 240Z 1969-1973
Here is the link for the OEM muffler listing: Part#15-J8101