pick some gears for me

Since its a O/D unit,you can afford to go to a higher gear ratio for take off and use a tall tire,28 inch to get back some of the top end.A 3.55-3.73 gear would be niece as it would drop down to a ratio of about 3.08 when you went into O/D,mrmopartech

You musta failed math. With the OD and a 3.55 his final drive ratio will be 2.59. with the 3.73 it will be 2.72. The OD ratio is .73.