Upper casting not same as OEM

[road trip]

I recently purchased an SE116 upper and lower unit through one of your distributors. Although I have not yet run the units on my boat (1993 Baja, 4.3 liter V6) I am very happy with the fit and finish of these pieces. My only concern is the water passage in the upper unit adjacent to the gears. Looking into the passage I noticed it is much narrower than the passage in my original unit. I ran a flow test on the passage and indeed it flows less than the original Mercruiser casting. Could this possibly cause a cooling issue while running? Is there some intent to this narrower passage or is it merely a by product of your casting/machining process?

Thanks,
Marco

[Tech Support]

The water passage is slightly smaller due to the casting process. We have not had any cooling issues.

Tech Support