I don't think you can add any more to the tunnel protectors. I also have a 136x1.25 track, the clearence between the track and tunnel protector is almost nonexistant. Also use studs of 1.70 inchs long with no problems, just a slight nick in one of the heat sheilds. But the only thing I had to add was extentions on the tunnel protectors to keep from catching studs on the cast alumnimun structure when hitting large ones. Good kuck.