What turbo for a 684 IH tractor?

[DPinkston]

I have a 684 IH tractor with the N/A D-239 engine. I know that they made a DT-239 for some applications, but they are apparently rare. I have been toying with the idea of slapping a turbo it. Since it is about the same size as a 4BT I figured a turbo for same would be about right. What turbo comes on the 4BT? Since I have no boost sensing feature on my injection pump all I could do is turn it up a little and watch EGTs. Any tips or suggestions?

Danny