Considering 3.73 to 4.30 swap
 

I have a 2016 CCSB 4x4 F250 XLT. Little less than 45k. Trucks been good and I’m satisfied with my DD vs towing performance BUT can’t help but think about the swap. Not necessarily asking about towing performance- I know it will really improve it. However, I want to swap both axles AND add a Detroit tru track to the rear ( currently the open diff). I also have the floor mounted 4x4 shifter. Nitro sells kit for $1100-$1300 with all you need (supposedly) . Quick browse saw true tracs in the $600-$700 range. So somewhere in the $2K range for parts. Am I off base here? Also, would I need to plan for other expenditures like speedo recal, ecm/tcm changes or stuff like that? Plus, I would love to hear more from those that have done something like this: positives AND negatives.... sorry if questions are silly just thinking out loud....Thankyou

Well, you would never get your investment back . . . . .

I would do 4:56 gears, add 37’s and a lunchbox locker to the front. Then you would have a real 4x4 machine.

Yeah, but a big, heavy truck like this even equipped with tires lifts and lockers is a 2nd rate (at best) off road machine. I think I’ll lean towards keeping it for towing and off road with vechicle better designed to do so... But, thanks for the reply.

Then just keep it stock, like this
https://cimg3.ibsrv.net/gimg/www.for...c24b0706a.jpeg

[QUOTE=timritchieblue;18737675]Then just keep it stock, like this
Pretty set up. I got an old IH Scout for my off-roader. The tru trac would be for wet ramps and dirt roads just getting on site......

I just did the swap. Only about 200 miles on the gears so far. I had a TruTrac installed in the rear (4x2), since they had to pull the diff anyways, I had them do the gears. 4 Wheel Parts did the install for $450 in SoCal. This is by far the best install price I could find, and I called several shops for pricing. I did pay an extra $150 for 5 year/60,000 extended warranty, figured that was cheap insurance. Covers the TruTrac and installation defects. Doesn't cover the gears I provided, but it does cover the installation/set up of the gears.

You can get the TruTrac from Ron's Machining Service for $620 to your door.

If you go with Ford OEM gears (4.30), the gears come with new ring gear bolts, pinion bearings, crush sleeve, and pinion nut. It does not say this in the OEM part description, so it was a very pleasant surprise that these parts were included. The Ford dealer I used (Varsity Ford) was about $380 to my door for the 4.30's. Aftermarket gears are that much, if not more, and you don't get anything with them; just the ring & pinion. All I had to buy to complete the install was carrier bearings, shims and fluid.

I'm on stock tires, and will tell you that the truck digs hard from a stand still, and I haven't even given it the full beans yet. It wasn't a slouch with the 3.73's, but it's noticible the difference to 4.30's. It holds gears better on hills, and over the first 200 miles I am getting better gas mileage. I'm doing a 500 mile test to see how much better the MPG's are, but I can already tell it's better by at least 1 MPG, maybe a little more. Of course, I've been easy on the throttle while breaking in the gears, so my right foot might be the reason for the increased mileage. I'm beginning to drive it more "normally" now that I have a few heat cycles on the gears, so we'll see.

If you ever plan on a little larger tire in the future (35's or such), I would go with 4.56's.

I bought a 3.73 truck. My dad ordered a 4.30 truck. I have since put on 37's and installed 4.88 gears, which gives me an effective 4.30 ratio with small stock tires. For wide open throttle speed, 3.73's are actually quicker with the high reving 6.2. It's well known the 3.73 trucks put up slightly better 0-60 times. But for light throttle around town cruising and normal red light pull outs, the 4.30's make it feel like you've shaved 2k lbs off the truck. It's an overall better driving experience. It also makes 5th and 6th much more useful when towing heavy on the highway. I've got several videos on YouTube demonstrating this. If you are keeping a smaller tire (~32"), then yes, go with the ford 4.30 gears. Like mentioned above, if you plan on going with a tire in the ~35" range, then go 4.56. If you go 4.56, then you will have to go aftermarket with Nitro or Yukon. Somethings you will need on the front axle are hub o-rings and spindle seals.(Edit- this doesn't apply to you because of your manual transfer case). They are almost guaranteed to leak if you reuse them. Ask me how I know.

Thanks Dan & Ron for the info! Esp the OEM parts guide. I’m seriously considering this swap- as stated my 3.73 gets the job done but am looking to improve or should I say customize my truck to our particular needs.

You may be right on a technicality as the 4.30 truck would have to shift twice to get to 60 mph vs once for 3.73's. But, I would bet that a 4.30 truck would be faster to 50 mph and to 70 mph.

Possibly. But the 3.73 gear leaves the truck in the upper rpm slightly longer, and that's where this motor makes a lot of power. Regardless, 4.30's are better for the truck, because they are never going to be race trucks, even if they are the fastest gas powered HD out there.

Truth . . . .