what shift kit to buy

So we took apart the 904 and it had a shift kit installed. That is what my friend said. There is a gold plate where a silver one should be is what he said. So how do I tell which shift kit is in there.

.............r u talking the transfer plate between the 2 halves.........more than likely a B+M............I use the Trans Go TF-2 kit..........kim.............