There are/were 2 kits IH offered for this. The Farmall 656 used kit # 534131R1 and the International 656 used kit #534130R91. IH changed the shifter cross shaft.
The shifter cross shaft (connects to the handle) was changed from having round drilled holes with round pins (press fit in), to round drilled holes with SQUARE pins press fit in.
The other problematic part I find is the 2 dividers, (404942R1). These wear and then tip/bind.