2003 f150 supercrew lariat 2wd 4.6 v8 8.8 rear axle with 3.55 gears. Want to regear for better towing should I go 4.10 3.90? Currently 70mph 2000rpm any help greatly appreciated thanks

 

4.10's all.the way... How much is the 4.6 rated to pull anyways? What are you pulling? I was towing a 7600 GVWR Travel Trailer with a 2003 Expedition 5.4 and 3.73's and it towed good. Just heard the 4.6 Expeditions only pull a max of 5000 pounds. The F150 can't be much different?

 

You may not be happy with that powertrain no matter what gears you put in. It's your money, but another option is to drive slower, take a few minutes extra. Or upgrade the truck to something 15 years newer, although that isn't cheap.

 

I ordered an F350, 18” tires A/T - does anyone know what brand of tires are on the 2020?

 

Exactly this. I went to 4.30 gears on my Excursion and it wasn't worth it. But the upgrade to the 6.7 in my signature was totally worth it!

 

I have 3.73 gears in my 2003 F150 with a 4.6 and it's great empty but for pulling a load it's just not the best choice and I don't think 4.10s would make that much of a difference, it's a great motor just short on power.
Denny

 

Sticker on the door says my F150 FX2 came with 3.31 gears and dealer list on sales said 3.73. How can I find out which is correct?

 

How often are you going to use the truck with no load in 65+ mph zones? That will make a difference in what gear you want. If you gear the truck to where it will pull decent, you will wind it out at 65+. You will have to go at least 4.10, probably higher, to get any kind of pulling at all. If a 4.30 is available, that would be better. I had a 4.6 Expedition with 4.6. It was a dog pulling a car trailer with a car on it. I hate to think what it would have been like with a camper and all the air drag.

 

Slide under the truck and look at the tag on the differential.

Denny

 

Thanks, that will be a simple end to the mystery!

 

I think 4.10 will put you around 2400 at 70.

Still quite short of peak power curve.

Cheapest is just to turn off od every time you tow.

My my family in the excursion v10 and 4.30 and rolling at 15k combined weight and I’d still like more gear to hold od on moderate highway hill climbs.

If if you want to make a dedicated tow vehicle, the most gear you can live with will help. And don’t over size the tires. If anything go shorter/wider than stock.

My next set of tires will be 265/70-16 instead of 75

 

I've found on this forum, a good number of guys have said they wish they had gone bigger, to the 4.56 when they got the 4.30. A few even said after they got the 4.56 they should have gone with the 4.88. Very few, like two (2), said they should have gone with the 4.30 after purchasing the 4.56.
This might help.

 

Been watching this thread since new, and everyone else has said lots. I'd personally say go with 4.10:1 or shorter (numerically higher) if possible.

The current tally seems to be:

4 >> Go 4.10:1 or lower (numerically higher) if possible
4 >> Completely unrelated questions or answers
2 >> Wrong drivetrain (appears the engine is too small specifically)
1 >> probably won't make much difference
1 >> generally folks in the Super Duty areas less often regret going shorter (numerically higher) than taller (numerically lower)

So, the tally seems to show:
41.6% go to 4.10:1 or shorter
33.3% unrelated, why did we post in this thread?
25.0% Naaaah

Back to the original question:
My $0.02 : If you're going to put money into this, go for the 15.4% increase for about the same price as the 9.8% increase. It won't be a glamorous difference, but you'll notice it struggling a bit less.

70MPH will be 2,308RPM, it will still shift down for pretty much everything, and 3rd will be 3,297RPM which a 4.6 can do all day long if it's in good condition. 70MPH would be 5,110RPM, and I wouldn't suggest doing that ever unless your 4.6 is built for it.

In the end, it looks like John Burton hasn't returned in almost two months after asking the question. Hopefully he does and lets us know what he went with. At least if others look at the thread, we've put a lot of good advice and some unrelated stuff out there for consideration.

 

Wow, that's more on-topic than most threads. Nice job everyone!

 

LOL I was thinking that too!