I'm in the seriously-thinking-about-it stage of repowering my Excursion V-10 with a 5.9 Cummins. If I go through with it, I will be rebuilding the Cummins and tuning it for some moderate HP gains over stock (Cummins = 305 HP and 555 pounds of torque).

To minimize having to mess with the drivetrain too much, I have narrowed my tranny choices down to 2: rebuild and beef up the 4R100 that's in the truck, or swap it with a rebuilt 5R110 that was behind a Powerstroke. The Cummins adapter plate is the same for both trannies. Also, tranny control is a non-issue. Regardless of which one I go with I will have to install an aftermarket tranny controller.

I have some questions:

1. If I swap in the 5R110, will it bolt into the same mounting points on the truck as the 4R100?

2. What would I gain with a 5R110 versus the 4R100? Obviously Ford thought there was something to gain.

3. If I keep the 4R100, what is the best build kit to handle the diesel's torque? I'm willing to do it myself if it's simple or I will pay someone else to do it locally. (I'm handy with a wrench but transmissions scare me).

4. Can I use the original transfer case as is, or should I try to get the one from a diesel. If I go with a 5R110 should I use the one that's already mated to it?

Thanks for any opinions,
Stew

 

https://www.ford-trucks.com/forums/8...eshooting.html Here is a link to some good info to help you decide.