would you need new driveshafts if i lifted my 1994 f150 4 inches

 

No they will be fine.

 

good up to 4 inches 6 inches you need drive shafts and extended brake lines, thats why i did 4 inch, just easier to do in driveway

 

6" will be fine also w/ stock shafts, you just have to worry about added vibration in a 2 peice shaft.

 

I would not go over the 4". I have pulled shaft out more than once with stock and 6 " lift .

 

No way would I go over 4 inches......the slip yoke in the driveshaft would make that puppey fall right out with even minimal flex.....not too big of a price difference between the two but even when u did the 6 inch not only would you need the driveshafts..might need to change the pinion angle of the axle as well as extend the brake lines and possibly the steering shaft.....there are always other factors than just the obvious....Luck

JR