BlueFlameEB

Traded in my 04 F350 6.0 for this 11 3.5 EB and my wife drives a Flex EB and loves it as I do on long trips.

What I am disappointed with is the off the line grunt of the EB in the truck. This truck is completely stock and no modifications are planned for it, but it may have to get 3.55 gears put in it. Currently has the 3.31 and they are great for interstate driving, but we have a lot of hills here and when the trailer and car are hooked up to this thing it needs to move.

Will be swapping the Scangauge into the F150 and monitoring. I use SCT as that is what I am most familiar with. Use BE2012 for the car, but that is not comparable and the SCT was used in the diesel.

Anyone swapped from 3.31 to 3.55? What was your reason and experience with the change? If you don't run stock size tires then please don't post as I would like an apple to apples comparison.

No, I don't expect the EB to pull like the diesel, but I also no longer tow the 24k-28k pounds, but instead will be near 8k. Hence the change, just hoping the 3.31 wasn't the wrong choice. Will know this spring when the car gets hauled to the track.

Now to go find a brake controller from Ford that actually works.

timtoolman

My 13 plat had 3.31 gears , I hated them in central Pa. Back to 3.73 gears in my 14 limited love the 3.73 much better. My 12 XLT had 3.73 gears , I related to your logic. I would go to at least 3.55

NASSTY

I was going to go through the trouble and expense of a gear swap I'd jump up to 3.73's.

Wannafbody

I have 3.55 and they are fine for pulling a 5500# trailer in western PA. If you are closer to 10k then the 3.73 are a better choice.

meaz93

You have to go 3:73 to tow comfortably. I know their are guys on here that run 3:55 with their 5.0's and like it fine. The max tow package bumps up the gear ratio to the 3:73 and on some FX's you can get 4:10 ratio , again better for towing.

SNOW.

Flash in a tune and be done.

timtoolman

I had a tune it still sucked with 3.31 . 3.73's definitely are better

meaz93

I had 3:31 Dana set up on my Titan, but that was with an anemic V8. Weird thing is it pulled my 8K+TT, but I really had to rev it up to climb those 6-7% grades. Now my F150 Boost with 3:73 makes it look and feel easy plus gets decent gas mileage to boot!

WTF150

This. If you are going to go through the hassle of a gear swap, 3:73s at minimum if not even 4:10s like in the tremor or you will regret it.

Adobe2X

I think that if you go to the 3.73's (which I too recommend for towing the kind of weight you are talking about)......then you are going to have to switch the entire rear axle, as the bigger gears will not fit in the smaller housing of the other gears.
Perhaps getting one from a junk yard all put together rather than try to buy everything over the counter would be best in your case?