new MSD coil makes a loud humming noise

[Mr 5 0]

richie:

Yes, as previously stated, the 'coil hum' you're hearing is fairly common with aftermarket coils, especially the MSD.

I have the Crane PS-91 coil and have never had any hum, but that could also just be good luck because in my experience, quality-control can be a little lax on some aftermarket parts, including coils.