Best rear end ratio?

[takehikes]

I have a 68 F100 short bed flareside with a 240-6, 3 speed manual and a 3.70 rear end.
I have zero chance of ever towing so would like to have a better rear gear for highway cruising.
Suggestions on what number would be best?
Its my daily driver and used out on open road on occasion but when I do I'd like it to not spin so tight.

[sargentrs]

As long as you're not interested in burnouts, a 3.00 - 3.25 has worked well for me.

[takehikes]

I was thinking a 3.00 or 3.25 as I read about a Galaxie of the same vintage with an automatic in it (and a 240-6) that drov ejust fine. Its a big pig of a car so I figured performance ought to be OK>

[sargentrs]

My Fairlane (289/auto) came with a 3.00 and I replaced it with a 3.25. Made just enough difference to make driving more enjoyable. My truck started with 3.00's and I upped her to 3.89's. Really woke her up out of the gate but she was screaming at 65 mph. Going back in 3.00's for more highway driveability and top end.

[jzjames]

For your sb flareside I wouldn't go less than 3.50, but I think the 3.70 is better. That is unless you're going to do major drivetrain modifications for a more modern type of ride.

For in-town driving and occasional highway, wouldn't you rather have the power to wheel around and accelerate?

I considered changing differential on mine w 300-I6 but glad I didn't. My highway driving is at 60-65 mph but I can chug out of a stop light and beat new cars.
And with the Offenhauser intake, efi exh. manifolds and 2bbl Ford carb, its ''awake" enough for me.

[Red Mercury]

I have a 67 Mercury 100 with a 240, 3 speed manual and 3.70 gearing. The truck has been in the family since new and always had terrible gas mileage--low teens. I changed the gears to 3.00 and found that the little 240 just didn't have enough power to run those gears for my liking. I then went to a 3.25 gear set. Even the 3.25's require a little bit of riding the clutch to get it rolling and it lacks power on the highway. The truck will not hold speed on a steep hill. Passing another vehicle takes some time & distance. Gas mileage improved by approximately 3 MPG. I am going to put the 3.70's back into the truck. Every 240, 3 speed manual truck that I have seen came with 3.70 gears and I now understand that Ford did that because it was the best match for the 240.

On another note, my father had a 69 F100 302, C4 automatic with 3.25 gears (factory) and it was much better. Much more drivable. I attribute that to the 302/auto combination. Mileage was much better at just under 20 MPG.

[takehikes]

thats the kind of info I wanted. Since I am not going to modify the engine at all I'll stay with the 3.70's and deal with the noise and MPG.
I know if I modify the engine and drop a 5 speed in it that it will be a much better combination but I am trying like heck to keep the truck as stock as possible as its a virtually unmolested rust free 68.