I just got a used plow for my 89 F150 and I have a friend that says I should really consider getting some air bags to help the front suspension. My truck has coil springs in the front with dual shock absorbers (I don't know if that means heavy duty springs?). I measured when I lifted the plow and the truck only dropped 2 inches. I think it would be ok but does anyone else think that's too much for the springs to handle?

 

Only dropping two inches with a plow is not bad, I have seen some F350 drop more than that even with the proper plow packages.

 

If you are concerned, find a pair of the stiffest hd springs for the truck, I think Moog makes them, look at the spring number, and the back of the book has the rates and tail type, find the spring with the heaviest rate, that might help.