There is a fundamental problem with the tool. Problem is the hole through the gearcase is not the same diameter on all cases. A 5/16 will go through some, but others it won’t. I discovered that when a customer busted a gearcase by pounding it through anyway. The factory tool is necked down for that reason. I then made mine as large as I could and still go through the smallest hole I found. Mine still ended up larger than the factory tool. Bottom line is make the tool small enough to go through the hole and it broaches through the bushing. That’s why I quit making them. Good luck.
EDIT; The OMC tool I bought was 0.277″ diameter.
