i would like to up grade from my 1991 f-150 5.8l. to a 1997-2000 f-150 ext. cab short box 4x4. with around 200,000km or lessNot sure what would be better The 4.6l or the 5.4l. i do some pulling and i hull water 200 gal. tank but of course i want the fuel economy. i do plan to put achip init. what is there to really look out for.

 

I'd try to read-up on them a bit. I've heard of people thinking the 4.6 was a little under powered when it came to towing. I had an expedition with a 5.4 and I pulled a '70 Bronco from GA to WI and you could hardly feel it behind the car.

 

My '97 F150 is a 4.6L and my '05 Expedition is a 5.4L. The 5.4 is definitely more powerful and as such it's better for hauling but it's absolutelybrutal on gas.. I get about500 kms on a tank of gas (highway driving, not towing).. it's a 102L tank. Afriend of minehas a 2001 F150 5.4L and his is just as bad as my Expedition..Ford's 5.4Lengine seems to be notorious forpoor fuel economy.MyF150 will haul quite well and is MUCH better on gas, but it lugs a bit. (We typically haula fully loaded 10' camping trailer with the box of the truck full; as well as logs on a flat-bed trailer every now and then. It does the job.)

My two cents. Good luck!