i have a 12 bolt housing #are bm1303g2 can anyone please tell me what it was thanks

bm1303g2

BM=3:31;1 gearing open non posi unit
13=?this should be the month code. Last I heard theres only 12 months :D Check the numbers again
03=day--3rd day
G=Assembly plant, Detroit Gear & Axle
2= 2nd shift

could have been in a few different cars. 68 Novas/Camaros--69 Novas/Camaros BM also shows up for a 65/66 Chevy II rearend also

LETS TRY BM1203G2

also if it didnt come with a posi can i have one installed

month is december then.

Yes you could get one installed if not done already.