1973 Duster with make over

Im always learning and like getting new info on things i would like to know more about. I feel you have a lot of knowledge im just not understanding why your sugesting what you are. So you say the pinion Should be centered in the tunnel. What will happen if not? I know the driveshaft wont hit anything through the suspension travel unless my suspension compresses tons, but in that case It will hit my rear crossmember first. I have checked mutliple times. Are you then suggesting it will cause vibration or some other erratic behavior? You just keep saying you would center it with no explanation or its my choice. Would you center it just for looks and it being in the middle of the tunnel because you like it like that or do you have information it would could a drivetrain or handling issue?