I have the R8 coils and they have been awesome so far. Only issue was cyl 5 misfired and I found oil, hence the valve gasket I'm doing at the same time. As far as water, I've never had an issue and I've had them in both Florida and Kentucky so not dry either place. Only other issue was the occasional short to ground which I will hopefully be solving with e30mclow's solution. The R8 coils work just fine, and seat so tight that I have to lever them out so as long as you have the spacers you should be good.
Bookmarks