Originally
the muffler on the 67 2000 and 68 1600/2000 was mounted
directly under the drivers seat. Not only is this a
hassle to remove and replace, it puts a heat source right
next to the floor. This is made more dangerous by the
rat-hair mat Nissan used as insulation. It collects
departing engine oil into a nice basis for a future fire
disaster.
When
the 69's were designed; the exhaust was converted so that
the muffler was mounted farther back, just in front of
the rear axle; like the part above. The front pipe that
connects to manifold, and the rear resonator are the same
on all cars. The center pipe was changed, as was the
muffler, which now comes attached to the axle "hoop"
pipe. As long as you order the muffler and hoop, and the
center pipe, you can hook up to your original pieces. The
67-68 system was eventually discontinued; replaced by the
69 style pieces.
All
of the hangers remain the same on both
systems.