This is a NEW oil pressure gauge.  The IH part number reference is 121606C2 and 121606C1.

It will fit the following:

786, 886, 986, 1086, 1486, 1586, Hydro 186
3388, 3588, 3788, 6388, 6588, 6788
3088, 3288, 3488, 3688
5088, 5288, 5488
4386, 4586, 4786

Also combines: 1420, 1440, 1460, 1480, 1620,1640,1660, 1670, 1680