On a side note, I have seen where you can put a set of 3:73 in a 4 series carrier, and also in a 3 series carrier. I am thinking of putting in a set of 3:23 or what ever is around there into our 66 Burb which is a 12 bolt truck with 4:10 in it. If I find a rear end with 3:73 gears in it, how can I tell wether it is a 4 series or 3 series carrier? I would be looking for a 3 series.
