1967 MC 1, startup issues.

After 20 months of rebuilding the old girl we started her up yesterday. I haven't been this excited since the birth of our first child.
The I/O is on the boat. Did a leak check last week and found water in the lower end. Fixed that issue. Thanks again, y'all. Took some time to get her adjusted but she is purring now. Old gas I imagine.
Checked the oil in the outdrive and it is clear blue. No water. Good news. While we were running I noticed the outdrive was making noise like two nylon gears. A smooth sound, not anything to draw ones attention but I did not imagine the unit would make noise. I checked the oil and it is topped off and clear. No metal flakes either. The outdrive has been completely rebuilt. When we shut it down I felt the outdirve. It wasn't hot or out of sorts. I just did not expect the noise. The noise is a smooth meshing sound. That is the best I can describe it. Need I be concerned or I am I just being a new Dah?
Regards,
TxGalz Dah

Ayuh,... Noise is created whenever you roll abunch of gears,+ bearings around,...
I'm guessing what your hearing is Normal..

This is my 4th boat and my first I/O. I reckon I'm a wee bit gun shy after all the blood sweat and tears. She may be 44 years old but she looks good in the water. I have dragged her to three different places and folks just want to come up and talk about her. It is kinda nice after all the work. Hose House 7 just refers to her as "that GDB".
Regards,
TxGalz Dah

When NEW gears are installed they can and do make noise.

You may be on the tight or loose side with your gear mesh, (dont know how well they were set up)?????

But in general if they are set up correct the noise show deminish as they "break in".

So assuming they were set up correctly this noise should be normal.