Check out this article by Pettifogger: http://www.theopenrange.net/articles/togglelink.pdf
and it will answer all your questions about what lengths a toggle link will digest, with pictures and everything
Your rifle will probably digest that Winchester ammo fine. Longer ammo can feed somewhat smoother, and 1.55" should feed fine as well. Most bullets crimped in their crimp groove will feed okay unless it is a really short bullet.
Enjoy your yellowboy.