If your study is actively acquiring more data, you may want to look into your protocol and optimize the FoV prescription, as you are acquiring a fair volume of just noise.
Other than that, I don’t think you should reslice the images at all. Maybe crop out Y and Z to 255 (if you crop to 260 you still won’t be able to use the high resolution recon-all). Please do not reslice the data, just crop the data array and update the affine information if necessary.