Upgrading rear axle ratio

[Johns Summer of 69 14]

When completed this will become my daily driver. Right now its slow to get moving and I want some more punch if/when I give it the gas. I believe it currently has 2.80 ratio. I am in search of trying to get the best of both world's with maybe leaning more towards optimal hwy driving. 

It is currently 351 Windsor, 4-barrel Holley with edelbrock dual plane intake, FMX transmission, 2.80 gears. My plan is to get something like the Holley Sniper EFI setup and an AOD transmission.  So I was thinking something in the 3.20-3.50 range should "wake" it up without sacrificing going 70mph on the highway. What would be your recommendations?

My daily commute is about 1/2 hwy and 1/2 in-town driving each day. 

[jholmes217 65]

An overdrive or 5 speed will be more forgiving if you have a high gear ratio.  I used to have a 66 Mustang with a close ratio top loader 4 speed and a 4:11 rear end.  The tachometer would say more than 4000 rpm when doing 60 mph, and you don't want that for a daily driver.  If you stay with the FMX, I would go 3:25 or 3:50 gear ratio.   An overdrive or 5 speed will be more forgiving if you have a high gear ratio.

[barnett468 418]

3.25 or 3.43 only . 3.50 is too numerically high for your app.

[LiLMike 42]

Mustang Mach 1s came with either 3:00 or 3:25 gears. I have a 4r70w with 3:55 gears. Depending on tire size, I should turn 2200 to 2500 RPM doing 70 mph. Haven't had it out yet but there are calculators to figure it out.

[1969_Mach1 333]

1 hour ago, barnett468 said:

3.25 or 3.43 only . 3.50 is too numerically high for your app.

True.  3.50 will be slightly too numerically high (ratio too low) for the way you want to drive the car.

Holley's Sniper system does not had provisions for kick down linkage and will not work for your application, I've looked for a future project that has a C6 trans.  Look at Holley's Terminator systems.  They are setup to work with Ford auto trans kick down linkages.

[Johns Summer of 69 14]

Not sure if this helps or not but I currently have 18 inch wheels. 

Would the FiTech EFI setup work better than the Sniper EFI?

[Sean D 31]

I went with the Strange rear end and axles when I swapped out my c6 with a AOD. True Trac with 3.70 gear 31spline. Love it and not too low gear with the AOD over drive.