Problem with ignition module- Should I replace everything ?

[cadeco]

I have a 5.7 Mercruiser and the ignition module went bad ( by my mechanic). I was thinking of sell the boat in order to buy that expensive part, but it's out of stock everywhere so, I will keep the boat. I was told that I could replace the system w/ a Delco marine EST kit that would throw away the Merc Thunderbolt module and would cost much less. Is that true? What do I need to do that? another coil must be purchased or can I keep the old one? My Mer/Thund. part number ( replacement) is 15899T01 ( just in case someone needs to know). What you guys think about that?
Thanks for all answers in advance.

 

[gm280]

I did a little searching and it seems you are correct about it being out of stock. However, EBay has a few listed for less then half the new cost. Not sure if they are warrantied or not, but if they are, could be worth your time taking a look-see.

Also, exactly what is the engine doing, or not doing, that makes you believe the ignition is bad?

 

[alldodge]

Have you verified the module using the TB troubleshooting guide?