Rear end gearing tech question

How tall are your tires and how fast do you want to run on the highway?

I run the Lunati cam one step up from that in my Duster with an NA 340. Ported 308 iron heads flowing 264cfm, 9.8:1 compression, dougs headers, eddy air gap intake, 750 double pumper and a 4 speed. Cam is
I run 3.55's and 26" tall tires. The cam wants more gear, Lunati recommends 3.73's for the cam I've got, but with 26" tall tires and the amount of time I spend on the freeway the 3.55's are about as low as I want to go. I can do ~75 mph at 3,500 rpm, so cruising on the freeway is usually between 3k and 3,500. That's about as wound up as I like to be for long periods of time.

Now, if you're going to run taller tires, or aren't worried about being able to do 70-75 mph for long periods of time, the 3.73's should be fine. Where I'm at in California if you're doing less than 65mph on the freeway you're a speed bump, and traffic usually moves closer to 70-75. With a daily driver like mine I'd rather have the cruising speed be where I need it and work out the first gear take off with the clutch. Either way, your engine should be just fine with the 3.73's unless you're rear tires are real tall.