Bought a 47 merc with a 10 bolt. I,m not a Chev guy. I'm told the reearend is from a 73 Nova with a 2.56 open gear. Is this a 8.5 or 8.2 gear? What about splines? 26,28 30...? I'm trying to avoid taking this apart until I have the parts to put it together the way I want...3.73 posi