Hey all,

Have a 2002 Ex with 7.3 - see signature for specs...
I want to move to 37s and 17-18" rims (not decided yet but definitely want to dump the 16s). I know I should update the differential ratio to get me back in the right power band. I think 4.56 would be about right (taking into consideration the heavier wheel tire combo)
This truck is not going off-road - that is what the Jeep/ATVs are. I just want to upgrade.
In a perfect world I would update to the later model coil and do it all at once, but I have a leaf spring Dana 60 front with 4.56 gears from 2003 SD complete sitting in the garage. Technically that would mean new springs and a R&P for the rear.
I am wondering if the cost of going coil is worth it - considering what I have. I also don't daily driver her anymore so throwing $$$ would be harder to justify...
Missing anything in my logic?
Oh - and what springs should I get to fit a 37s? (again no hardcore off-road) Worst would be crappy dirt roads with trailer full of ATVs or Jeep to get to parking area!

Thanks!

 

If you already have a front with 4.56's sitting around, seems like a real easy choice to me. I'd just regear the rear Sterling (maybe rebuild the factory limited slip or replace it with a TrueTrac while I was in there).

As for springs, the go-to used to be the pirate pro-comp lift recipe, but from what I gather they're no longer being made/ sold. I know people love to hate on Rough Country, but I've got nothing but good things to say about their stuff. Yeah, they're the Walmart equate brand of lift springs, but everyone used Walmart equate brand products because they're cheap and they work just fine (just no brags about using them). Sure, there are way better springs/ lift its out there, but for the price, IMHO its real hard to beat Rough Country in a non-hardcore application (which is most vehicles). Maybe use some better shocks for a nicer ride, but Rough Country springs are just fine.
...

 

never tried it, but I don't think the Excursion will accept 18" wheels and tires, unless it gets Lifted up ...

mine has 16" 285/74R tires and they fill up the wheel well.

 

@Toreador_Diesel has had some experience with a 7.3, larger tires and different gear ratios.
If I recall correctly the rule of thumb to keep from over revving the 7.3 is 4.10s for 35”s and 4.30s for 37”s. 4.56 gears may have you spinning that old oil burner a bit too high if the local highway speeds are in the higher range, here in the Mid-Atlantic region the max is 65 MPH and that’s only on a few of the highways, 55 is the norm.