the link to mercruiser info has on line manuals by year and engine.
I am assuming you have a timing light & know how to use it. The timing marks are on the the font of the crankshaft on the harmonic balancer ( just behind the pulley).
Depending on your boat engine compartment, unless you have some good mirrors, a snake-eye camera, or are otherwise a contortionist, it can be a challenge to see that tab up there on the housing.
There is no tab as in the older engine. You have a notch in a boss cast into the timing cover on your engine. It's for 0? TDC. You need to use an advance timing light to set the timing.
Here is the procedure for setting the timing on the Thunderbolt V ignition system. 10? BTDC is what you set yours at.
I have that same page from the manual. I don't see that darn notch. I will look some more when the sun is back up. Either I am blind or something is blocking it from view.
