Technical Mopar starter I

I have a 230 dodge six with a wilcap adapter to a turbo 350. It uses a modern mopar starter. Wilcap says starter engagement should be 1/2-2/3 engagement across the ring gear, which is 3/8 wide. Mine engages 1/2 across the ring gear, which makes engagement 3/16. Wilcap says this is factory spec. Seems like kind of a light engagement to me. I can mill the adapter and bring the starter closer to the flex plate. Knowledge of engagement or opinion would be appreciated. Thanks