Tach and Temp on a 1980 40hp Merc?

[jdrautoworks]

Well I am looking to add a temp gauge and tach to my 1980 Bass Tracker III 16' and it has a 1980 Merc 40HP S/N 5661770.

I will be honest I am completely lost on where even to begin. I will say that I am a auto tech so I go out on a limb and say I am mechanically inclined.... :shock: But outboards are like spaceships to me...

Anyone willing to help me thought this?

Thanks in advance,
Jerry