[Hozer 88GTConv]

If you really know/think you have a busted oil ring, I'd back off and fix it.
I lived with a bad broken oil ring on number 5 for over a year and kept telling myself that it might have been something else (bad intake seal, valve seals, guides, yatta..) I can't tell you how many plugs I changed and those stupid anti-foulers are a waste.

A bad ring will foul your plug right away, cause fuel to dump into the cylinder, and burn in the exhaust.
If I had to do it all over again, I would have just dropped the pan, pulled number 5 rod/piston out, re-ringed it and stuffed it back in the hole.
good luck...