On the Kaili 85 300D with the Trap Oxidizer, the exhaust goes through the trap first, then it goes through the Turbo to spin it. There will be an exhaust temperature drop going through the Trap first.
The best way to change the 85 Kali 300D, is to install the Federal Manifolds, Down Pipe, Turbo and Turbo Oil supply line. The Exhaust then goes directly into the Turbo from the engine to spin it, and then out the exhaust.
If you can locate some 78 - 79 W116 300SD none EGR manifolds, that would be better.
Charlie