Gearing right now it has a sure grip 3.73 741 case which I want to get a 742/489 case with probably 3.55 to get closer to highway speeds at not a ridiculous rpm and make it stronger for the higher hp engine.
Waste of money on the case unless it's the change of gears and you can find a deal. IMO. If you have to have the other cases, find one with a 3.55 set and swap the sure grip into it. The pinion thing is one of the biggest sack of BS in the mopar world.