I'll be interested in your bore measurement - if it is only 0.003-0.005 oversize, taper should not be an issue, and ring gap will probably be reasonable as well. I'll also be interested in what the bore looks like, of course, but it is sounding positive at the moment.
In case it matters, those unsuccessful V8 rings had the SS55 expander that Repco used to sell. To be fair to Repco, they sold good expanders as well, the SS55 was a cheaper line they pushed hard. I should have known better.