I know on some of the newer trucks they have adjustable coilovers to achieve any measure of lift between 1 to 3 but new spacers for up front arent that expensive. If you like your ride quality now nothing will change with the spindle lift. So if it doesnt bother you now leave the 2.5 in there.

 

If you don't plan on going over 33s, 6" of lift will look pretty dumb

 

So if I leave the 2.5, get a spindle, and then get new tires?

 

try it that way and see if you like it. If you dont then tires are always an option.

 

Would a 3 inch spindle from rough country do?

 

If i were spending that much i might would save and get the full kit with blocks, shocks, and u-bolts.

http://www.roughcountry.com/ford-sus...it-528-20.html

 

So that'll be 5.5 inches of lift right?

 

That would be correct and it will stay that way if you have aluminum spacers. If not then they may settle a little bit.

 

5.5 inches on 2wd is different than on 4wd too right?

 

Yep. 5.5 will get you a little higher than a stock 4x4 without turning up the torsion bars. You put that much on a 4x4 and 37's will fit without much trouble.