833 question

Hey i just put a rebuild kit in my b body 833 trans and it all went well, i installed new syncro rings, bearings, sliders, keys, now I have one question, it seem to up shift ok, but when i down shift into second i get a little grind when it goes into 2nd gear. It only does it when i pull pretty hard on the shifter, if i don't pull hard it wont go in at all until slower speeds. What do you guys think? Thanks