From someone who's tried them all,
the best Ranchos are yellow and blue and say Bilstein on them.
The Bili 5150s will sit right between the Rancho pricing, and they will last longer, ride better and NOT LEAK like the 9000s.
Mbeach are the 5150's close to stock in stiffness?
My Rancho 9000's have been going strong since 2003. Daily I put them thru punishment that destroyed the stock Isuzu KYB expansion chambered shocks. Over 5 years without a problem using Rancho 9000's.
NAVIGATOR
Steve
Transio posted a good link.
I wish that my experience with the 9000s were as happy as Navigators, but mine were just the opposite.
First off, the in-cab controller was a turd. Leaky connections (yes, I'm a good wrench and did them correctly), etc. It simply allowed adjustment from a bad to worse ride.
I machined a new manifold for the system, hoping to eliminate some of the leaking fittings, and allow for integration with my on-board air system (which had a far better compressor), but never got around to installing it, because-
The shocks blew their oil out at <10000 miles.
Granted, 4000 miles were spent driving up the Alcan, at a high rate of speed, controlling large tires, and another 1500 were used up on the Steese, Elliot, Dalton and Denali Highways (all gravel, ruts, etc), but the killer was winter.
One day the ride felt even softer than usual, when I looked under the truck, there was oil everywhere. It had actually made its way past the piston seals, and was shooting out of the boots during compression.
The wife's Bilsteins endured all of the same hardships, even towing a 4000 pound trailer 4000 miles across two mountain ranges, and they looked and rode like brand new until the day we sold the truck.
I was very dissapointed with the Ranchos.
Avoid the hoses and the fancy in cab controller, I hear nothing but bad things about that in cab set up. The Ranchos are really good shocks, set them once by hand to 9 (max stiffness) and forget about it
I 'test' the Ranchos daily over the same stretch of road that killed a stock KYB aluminium shock with expansion chambers, The road has gotten worse over time, but the Ranchos continue to overcome the torture. Avoid the in in cab device.
BTW I've heard good things about the Billi's, but have not tested them.
i would not recommend getting the 5000 series ranchos. they are way too soft compared the the oem shocks. i changed all four shocks to the 5000 series thinking all my shocks were bad. ends up only my left rear was blown. the rancho front shocks were way way way too soft and the vx would dive and dip alot so i ended up putting the oems back on. i kept the rancho 5000 on the rears but i suspect that they wont last very long. i will prob go with the 9000 or bilsteins once they blow. unlike the oem shocks the rancho 5000 does not have any positive force pushing the wheels to the ground. it just is a resistive damper where as the oems are more like a gas spring.