This is a bit of an unusual update, but here's a first-ever upgrade for the W116 chassis:  300E seatbelts.  Why a seatbelt upgrade,

you might ask?  Well, the female end of the seatbelt attaches to the seat itself on a 1979 6.9, whereas the 1976 450's attach to the

transmission tunnel.  Since my original 6.9 belts were damaged in the fire, I just left the 450's seat belts in place and simply removed

the 6.9's female end from the seat frame.  This works.... but the seat design is different enough between the seats that the 450's

female end rubs and squeaks like crazy against the leather of the 6.9's seats. 

removing the belts from the donor 300E...

Here's the old mechanism next to the new one.  Note the pyrotechnic exhaust (not hooked up).

...and mounted.

The b-pillar connectsor sits a little lower, so the metal rings were removed to be shaved down at a later date. 

The belts clear fine without them now... all it took was a little bending and a lot of swearing. 

The driver's seat still with the 450's tranny-mounted seatbelt...

from the back...

The 300e's female end attached to the passenger seat.

...and finally, replacing a broken clip under the drivers seat.  Leave it to mercedes to not mess with a good design...

the clips from the 1993 donor car were perfect replacements for the '76 W116. 

Dyno day!

Getting clamped up...

Ready... set...

GO!

Here's the chart:

As you can see, I pulled 205.81rwhp, and 310.08rwtq...  pretty much what I figured.  Using an

18% drivetrain loss, that translates to about 242.8hp, and 365.9tq. The curves were extremely smooth,

and both dyno runs were right on top of each other.  The air fuel mixture was spot on, and fortunately

no issues came up.