Converter and gear swap.
Yeah what you can tolerate on the street is going to differ from the next guy for sure. To me, 4.56 with 26" tires on the street is going to see a lot of revs. Unless you're just cruising around 40 mph roads then it probably wouldn't be a big deal. If you're hitting any highways, I'd expect some high rpms which may or may not be tolerable to you. For the track with 28" tires, I'd expect that they would work well, although they might be on the tall side? I don't know a whole lot about your setup other than your sig. Have you had it down the track before?