The 87 came from the factory with the blue packs.
They updated them to the black sometime after 89 (?)
To use the blue you'll need to have the blue coils.
The connectors are different on the lead to the coils.
They say don't mix the black and blue.
I have and never had a problem, just change the connector ends or use a butt connector(probably a better idea)
You say BOTH black boxes died??
That doesn't usually happen.
outboardignitiondotcom has test procedures for your motor.
The black might have the CDI letters on them somewhere?
This might mean the stator has been changed too.
The test results for CDI products(stator) is different from OEM.