u/Ahov1225

I have a cheap rw Jameson banjo that I want to change the head on. It seems to be an 11 inch head medium or low crown but I ordered that from gold tone and got a head that is a little too small to fit. I have loosened the neck and made sure the body isn’t out of round. The new head can fit inside the old one and jiggle a bit. I think I may need a low crown instead of a medium but would that affect the diameter at all? Please any help figuring out what I need to order to get a renaissance head on this banjo would be much appreciated.