ANYTHING N scale will run on Peco code 55, as far as flange depth. That's the idea behind their rail design. The only real problem is that modern American wheels don't always like the guard rail spacing, and that can be fixed with strip styrene shims on the inside of the guard rails.
When I was laying my staging yard, 20 years ago, I also found that some of the turnouts had angled ends on the points. Those allowed small-flange wheels to run up and over the points, rather than following the as they should, causing split switches. Other turnouts, with the same part number, had square ends, and worked fine. I don't know which was the newer design, and haven't bought any since then, so don't know if it's still an issue.