Thanks to all for your advice on my last post RE the 280 twin-cam 6 that had retarded timing.
In order to get this car really right, it needs the front exhaust manifold, which also is a cat converter, replaced due to a split in the stainless steel outer housing.
My local Mercedes garage says they are no longer available new from M-B, and since it is illegal to install a used cat on a car, he has suggested using a manifold setup from a 1978 or later engine and a new cat installed on the tailpipe under the car.
This would allow the use of the A.I.R. plumbing to keep it legal, as long as a smog referee approved it.

Has anyone tried this fix, and if so,what are the costs/pitfalls associated with it?
Thanks,
Nate

'79 300D
'86 F-250 6.9l Diesel

I'm not sure if your engine is the M110 twin-cam six, but if it is, you may be able to fit a Neutronics Bosch K-Jetronic Upgrade Kit, which is designed for the later W123 280E and massively improves emmissions performance.

This kit is supplied ready for installation and consists of a microprocessor controller, wire harness, Bosch fuel control valve, heated oxygen sensor, and a universal three-way catalytic converter. It is legal for sale in California, and you'll find more details at http://www.neutronics.com/bosch.html.

Chris,
Thanks for the information- Unfortunately, this car has the 4BBL Solex carburetor that so many techs on this forum love to hate.

Actually, the carb was recently rebuilt and seems to be dialed in pretty well, it's just the exhaust leak and resultant excessive heat near the engine that needs to be fixed.

Any other ideas out there?