Hi there, did your topic title mean to say convert vs covert? If so we can change that for you.
Being if your engine truly is a 1997 engine model, then your ignition system is (should be) already an electronic ignition system known as Mercruiser's thunderbolt 5 ignition system that uses an electronic ignition module for timing advance, etc.. Here's a few images of what the TB 5 system should look like,
http://www.rinda.com/gifs/DESA5.JPG
http://thumbs1.picclick.com/d/l400/pict/271591102444_/Mercruiser-Thunderbolt-Ignition-System.jpg
If the engine is 1987 then it might depend on what system ignition system you have as far as resistance wires going to the coil goes but even in 87 Merc was already using electronic ignition known as thunderbolt 4 so doubtful you'll have one.
Is the engine 4.3 L, LX or LXH?
Is your engine serial number handy by chance?
If your having issues with you current ignition system and are done fighting with it, There might be an easy to install aftermarket marine electronic distributor ignition system available that we tend to often refer members to that one of us could recommend for you if desired via a website link.
