Ignitionman(he builds small body HEI's....Dave Ray) is a very big fan of that napa coil.
Its a good performing unit, but it seems that its reliability is one of the main factors that he likes this one.
If you have the MSD and there is nothing wrong with it...Id personally run it.
Here is the disclaimer though... Not just MSD, but as a whole, oil filled coils are no longer made in the USA(many of them used to come from a factory in Indiana). The EPA said no more.... whatever fluids are used, they deemed it to be a hazard. So, lots are now produced in mexico, and many in China(oil filled deals) and other Eastern nations.
He complained of prominent layer shorting issues with the chinese made units, which can fail the ignition module. This may or may not be as prominent of an issue as it was a few years ago when production was first moved.
it might be a mexico made one too, which I havent heard as much "bad" about. Seems like the complaints were centralized around the china and some of the other eastern made ones.
So, take that for what its worth. Like I was sayin though if I had it....Id try it. If it fails prematurely, it wouldnt bother me that much as were not talking about high dollar items
