I just had a th400 rebuilt besides for the b&m reverse manual valve body it has. Now the shift pattern goes P-1-R-N-2-3. Any help would be appreciated?

Got a ball in the wrong groove in the valve body?

that isnt right it should go p r n 1 2 3. maybe as andy said a checkball in wrong place or something else it has been a while since i installed a reverse valvebody. if you got directions for it post them or pm them to me and i can help you out on it.