i lost about 3mpg all around with my 6 inch lift and 325 65 18's

I have other stuff done to help MPG's too. It was all done pretty much the same time so I don't know what it would make not lifted.

Im glad I asked the question! The springs sound like a good way to go because the truck sits low in the front.I have a v10 in it if that matters?? I will check in when I get a chance and let you know how I make out. Thank you !

Are the spring blocks ok to use in the front? I recall hearing not so good things about blocks.If not I guess positive front arched springs are the way to go.

NO BLOCKS IN THE FRONT. The f 250 stock spring is about 2-2.5 inches higher than the stock Excursion spring, and the one you want is the X code. On some you my have to play with the rear spring or block to get it to sit level but all them I have done we got lucky and did just the fronts. If you have a 4X4 shop around go ask them if they have any laying around from a lift they did. I know the guys around here get them all the time.
Then you can run up to a 35-12.50 tire on a 8.5 wide wheel. Sometimes you may get a little tire rub at full lock turn with that big of a tire, and I wouldn't go wheeling because you wont have a lot of travel but it looks nice and if you tow a big boat it gets your frame as high or a little higher then the trailer frame and it tows better.

check tire pressure as well... if it is off even a little, it will wander like a mofo.

Im running BFG 275r16 tires and they are brand new.I had a good shop do the install but I havent put a guage on them yet.I swapped trucks with my wife this week,she drives my 07 f150 and I started drivinig hers and Im like holy crap!This problem has gotten more noticable in the last month so something is definately up.I put a 20 foot trailer on the back(dirtbike enclosed) and the thing pushes the front back and forth a bit.I could pull my 38 formula with the dually at 70mph and it was rock solid,this truck makes me hold the wheel with both hands tightly! Love the exc and I was hoping to tow the skater with it but not now.
I am going to call the 4x4 place tomorrow and see if they have a set of springs.

Good timely topic. My Brother has been using mine for the past month while baby sitting the mutts. Forgot after getting accustomed how much they wander, until driving it to Seattle yesterday! Brother did not like how it drove either, cause he goes: "you owe me. I'll make it an even grand!" Have not looked at the bill for what he had done, but, alignments where involved! :D

I put mine on the rack and it came back clean,only minor adjustment but Im going to get a second opinion.

Changing the front springs cures about 90% of the wandering, I've got a father/son team for customers that just went through this, the father used brand X shop down the street and they used a front spring bucket kit to get 2" of lift and the truck wanders all over the road, the son's truck we put a set of f250 springs to get the same amount of lift on and it drives great, both trucks same mileage/maint schedule and same alignment specs. Different wheels, same offset and same tires.