· Premium Member
The big bore kits are fun but they have a brief life. I would dare say that they seem to last half as long. Option 1 is what i would do and maybe reach out to Miller to see what cam options pair well with the port work they did or even get the head re-done with bigger valves and cams to match. Ultimately, I would reach out to a builder that still does the older YFZ's because they probably have a few good recipes.