We recommend the TG109 sight set for the Marlin 336. It is important that you measure the factory front sight dovetail insert for compatibility with our Marlin 336 sight set (TG109). We supply a front sight insert that is .343”, measured from the bottom of the dovetail to the top of the sight. If your front sight insert is shorter than .343”, or significantly taller, then we would not recommend to install these sights on your Marlin. These sights can be drifted in and out with a small hammer and a soft-metal punch or drift.
We always recommend to have an experienced gunsmith perform replacement sight installations of any kind.