I appreciate your reply Ken. I don't do diesels except for repairs at the LHS. Even when installing decoders, unless specified by the customers, I install 16V lamps in all the diesels. When installing those lower voltage lamps, I just install the proper resistor to lower the voltage.
Since he didn't specify the number of functions he would need, I gave him a decoder that would have enough functions he would want/need later. Otherwise I would have said something like a DH-123. That one is under $20 bucks. The DH-165 acts as a full replacement for the original circuit board, and is easier for me to install. There are no problems with room.