1976 Cobalt 235hp 5.8 ford electric shift?

Hello,
I recently purchased a 76 cobalt with a 235hp ford 351w.
I am changing sterndrive fluid and have read the electric shift lower units require C type omc fluid instead of standard 80/90 gear lube.
Sorry if this is a stupid question, but what is the best way to tell if this is a electric shift or cable?
I had it out several times last year and aside from breaking the shear pin on the prop, it ran well.
Thank you in advance for any advice on this boat.

Look at the back of the control box, you will see a cable or just wires or post a pic of the drive, a stringer drive is electric
the 800 type from 1978-1985 show as mechanical shifting. Cobra drive are mechanical shift

This is a picture of my drive.

I determined it is an electric shift drive. I used Type C high viscosity in lower unit, and regular Wal-Mart marine 80/90 in upper case, and topped up intermediate and clutch housing as well with 80/90. Should I have put type C in the upper and intermediate also? I read the type C is critical only in lower case.
I love this boat, runs well, looks great, but am nervous the more I read on this drive. I have worked on cars professionally for 30 years, but not much boat experience. Are these drives fairly reliable? I have learned nobody locally will work on it, so I am it if it needs fixed.