Hit a snag with the build the other day. Was swinging a locked centre into another housing from one of my previous wrecks, all roughly the same age, all 1.6, all manual. But there wasnt the same number of bolts going into the ring gear to just swap the centre across

. Both rings and pinion from each diff have the same number and teeth. Cant remember the number of teeth off the top of my head, just remember they where the same on each.
Woundering if they are the same gearing? Or if there is a definite way of diagnosing the gearing. Just want to be sure before i go dropping it back into the housing.