Olotti76

is it worth the cost to buy a v8 3.55 that has all one wants on it but knowing I need the 3.73 to haul a tt to consider the 3.55 and upgrade the rear end or is it not cost effective. I'm looking at a 2014 4x4 f150 xlt model with towing and power package on it. In the future and I believe I did the math right but a 5800lb dry weight tt with hitch, tongue and 400lbs of payload would put me around 7300-7400lbs total towing and the 3.55 is 7700 max so that's a little close for me I'd like to have the extra towing room at 9300 total towing with the 3.73. I'm not in a super hurry for the truck but I'm just having a hard time coming across these trucks with the 3.73. Here's the truck.

https://www.cargurus.com/Cars/invent...ting=182398806

Scrappy Doo

iTrader: (1)

I think most of the posts on here say it's around 2,000. Up to you

Simnut

Remember, I don't believe it will change what your truck is "rated" for. It may do the trick for you but make sure you are not liable if over on any of your weights.

jp360cj

What year truck are you looking at? 4x4 or 4x2?

I would say most likely not cost effective, but it's going to depend on how good of a deal you get on a 3.55 truck and your local prices for the gear swap. But 3.55 to 3.73 is only a 5% change and I doubt you'll notice that much difference. IF you get a 3.55 truck and already have the trailer, pull it and see how it does. If you still think you need lower gears, then go straight to 4.10s.

AZ_HighCountry_F150

Agreed....I can't see spending $1500-2000 for a 5% change. I can think of better things to do with the money.

SteveLord

Get the most gears you can right off the bat.

techrep

iTrader: (1)

Double that for a 4WD ?

jp360cj

I would expect $2k would be in the ballpark for front and rear. And (for a newer IFS truck), I suspect the rear would be less than the front because it's much easier to get to.

WXman

The parts should be $500. The labor should take several hours. So you should be looking at $1,000 to do front and rear, if the mechanic knows what they're doing. Heck, we've done a bunch of them in our 19x19 garage at home.

Having said that, 150 RPM on the tach is not even noticeable, so it's literally throwing money away to do a gear swap for such a small change.

chimmike

why do you need 3.73's if you have 3.55's?

I have 3.31's on my 17 and have zero problem towing a TT.