2001 Expy 5.4 vs 1999 F250 V-10

[Steve Hartman]

OMG! I bought a 99 Super Duty and can't afford to drive it! I have a 2001 Expy with 265K on it that has run like a top since I got it with 135K on it. (12-15 MPG depending on how heavy my foot is. Never had a trouble light! Drove the SD 173 miles and used 29.2 gallons of gas, for an average of just under 6MPG. My Expy is old and beat up body wise and I'd probably be lucky to get $2500 for it. But the drive train is very trustworthy. So I'm wondering if I could do an entire swap of engine, tranny, and xfer case.

I guess my first question is... is it doable and how hard would it be. I know the blocks are the same except for the two added cylinders. What I don't know is - are they added to the front of the block or the rear. I'm worried about motor mounts.

Second, my 2001 Expy has electronic AWD to 4WD and the SD is manual. Would I have to use the old transfer case and would it fit the tranny off the Expy?

And speaking of transmissions (believe SD has 4R100 with big pan bubble)

Would the 5.4 underpower the SD or did they make some with the 5.4?

Thank you in Advance! I appreciate it!

 

[JamaicaJoe]

I wonder what the final drive ratio is for the SD. Compare revs at 70MPh or so.

Sent from my SM-T350 using Tapatalk

 

[Aspen03]

6mpg on a super duty? If you weren't towing you either have a problem with your foot or the thing is in desperate need of maintenance. A friend of mine daily drives an F250 towing a 3200lb air compressor in about 80% city environments and still manages 10.7mpg over the span of 173k mi. He bought it new and mileage has been virtually unchanged and also idles quite a bit throughout the day. That's a 5.4 but the V10 didn't get 45% worse fuel economy from the factory.