I just looked it up. I didn’t see any big block that takes a tapered seat plug. Again, I just make a quick look but I don’t think that head takes a tapered seat plug unless it’s an industrial engine or something. Again, I could be wrong but I’ve never seen at tapered seat plug in any big block head.
Just trying to sort the plug situation out first. That’s where you need to start. With the right plug. Doesn’t have to be a Champion. I’ve been using them since 1972 so that’s what I have the most experience reading. Any plug with the correct architecture, a single ground wire and the proper heat range is fine.