Thank you for the replies. I have since found that apparently the L1A1's usually used a taller rear sight blade and front sight.

I originally asked because I like the idea of a folding rear sight to stay out of the way of my future scope that I intend to mount as low as possible. There was an Entrerprise L1A1 at my store and I considered swapping out sights. Of course the day I thought about swapping parts the rifle sold. I will be sticking with the original rear sight, snugging it up and it will be low enough to be out of the way.

Thanks again.