Oldsmobile Diesel Technical Magazine
There are a few different options available when it comes to exhaust systems on the 5.7L Diesel. Fortunately, since the exhaust manifold pattern is the same for all other Oldsmobile gas V8s, the use of headers is possible. Of course, it all depends on availability for the application, but there is no doubt that headers flow the exhaust gasses better.
With the use of headers, it will be necessary to have a dual exhaust system made...any custom exhaust shop should be able to fabricate the exhaust for the application.
With exhaust manifolds, it will be necessary to have the crossover inlet on the passenger side exhaust manifold blocked off. Chevy trucks powered by the 350 Diesel (1978-1981) have dual exhaust...there is a factory block off plate for the crossover inlet...These however have been discontinued and are no longer available from GM. The other option is to have that portion of the crossover pipe cut, crimped and welded. The second exhaust pipe from the drivers side will have to run across and along the passenger side pipe since the transmission crossover is in the way.