You are correct that you need the right flywheel. The 89-up 240 is the correct model. To be absolutely sure, count the number of holes in the ring- the new one must have the same number of holes. There are 2 different counts if I remember right. They are, as you've guessed, the trigger for the LH 2.4 crank sensor.
You will also need the driveshaft from the M47 car. Get a new rubber flex disk when you order your clutch kit. And apply some grease to the outside of the throwout bearing sleeve to get the smoothest possible clutch action. This should make the clutch feel "like butter!"

And that flywheel should get resurfaced if it's a used one.
Good luck!
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Rob Bareiss, New London CT ::: "Roterande Fläkt Och Drivremmar!"