With 3.38 final drive you may want to consider one with 4.03 1st gear if you: have tall tires, need to get started on steep streets or go on back county road that are steep / rough or require low speed travel. If not 3.76 1st is a good choise.
I've got the lower 1st in my '60 with 3.56 spicer rear axle. You don't use 1st that long on the street but it has saved the clutch and my nerves great stress.
