When I went from 3.73 to 4.30 gears I did OEM gears, the shop charged me the same price as I was getting for Aftermarket sets so to me it was a no brainer

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How was the pulling power and MPG after the change of gears to 4.30?

 

Me and Scaler both went 4:30 but honestly if I did it again I would have went 4:56 , my trucks primary use is pulling our fifth wheel. My MPG didnt change hardly at all with the swap..

 

The 4.30 gears will help, but leave the truck in Drive, turn on Tow/Haul mode and let the truck select the gear it wants. Locking in 4th gear doesn't hurt anything, topping the mountain pass wide open in 2nd gear is not damaging your truck. Let the little engine sing, it will reward you.

Oh, and skip the cold air kit. It won't do anything for performance.

 

I used Randy's Ring and Pinion for my 4:30 gears.....made a huge difference towing my 5ver.

 

Thanks guys looks like the 4.30's will be on the truck next month (wife said yes). She really hated the sound of the exhaust in 4th gear at 65 MPH.

 

I went with the 4.30's from 3.73's on the truck below. I'm running the stock tire size and I still occasionally wish I'd have gone with 4.56's. I bought Yukon aftermarket gears from Randy's and was very happy with the whole buying experience. Their after installation tech support was also superb.

I will warn you that the truck will search for gears from time to time with the 4.30's, and probably even with 4.56's, but the driving experience is so much more enjoyable with the 4.30's or 4.56's. The little 330 C.I. engine likes RPM and if you're bucking a stout wind or a reasonably steep grade she will ask for more RPM and the automatic transmission will oblige. You will not completely eliminate the searching for gears in normal towing conditions but it will be far, far better than the 3.73's.

Your unloaded gas mileage will stay close to the same as with the 3.73's (we lost 1 MPG unloaded) but I'll lay odds you will get better towing mileage with the 4.30's/4.56's over the 3.73. Ours went up about 15% to 20% (7 MPG with the 3.73's, 8-8.5 with 4.30's) after the gear swap to the 4.30's.

Good luck and I guarantee you will be glad you spent the money on gearing!!

 

I remember running 4.58's in my Chevy with a 327 V8 and a turbo 400 auto. Lots of pulling power for a small block. The engine would scream at 70 on the HWY since there was no overdrive. Since the 5 speed auto int he Ford has a lock converter and overdrive I doubt I will have this issue. My next long trip is early next year I will post on it to let other 5.4 owners know the difernce in pulling and gas MPH. Thanks every one for the first hand experiance and information it has really help make this decision. Great Forum.