I bought a Strutmaster conversion for a 1999 Ford Expedition I had previously... it had the 4 corner load leveling suspension, and it died at 60K miles... I was worried about more problems and more cost repairing the factory system so I searched and found Strutmasters. I thought I had the answer to end all answers. Unfortunately - the LLS Expedition has totally different shock mounts and distances in the front compared to a standard Suspension... so I bought the kit.... I had the truck for another 2 years and it was never right. It no longer handled very well (for an SUV) and road even worse now. Basically all the Strutmaster kit consisted of was the correct length shock with a coil over helper. I paid $250 for the front kit and when I got it - it came in a plain white box and had the same part number on it if I went to NAPA myself and bought a set of Monore SensaTrack shocks - happens that they were made for a 1966 Ford Bronco rear... and they had the correct dimensions for the Expedition front... They were noisy, road bad.. worst mistake I ever did to that truck... it was one of the contributers to me selling the truck before I was ready to....
from my experience - I will always try to stay with original style suspension on my cars.
FF