I just saw this post and realize you may have already solved your issue, but... We own an '08 Gulfstream 8295 on a W20 chassis. The front end has a lot of weight due to opposing slides up front. The axle is rated at 7500 lbs. and we have weighed in at 7400 on the front axle loaded for a trip. The front end used to slam up on every expansion joint for bridges or potholes. The dash seemed like it was going to come off in our laps. The previous owners put Koni FSD shocks on the front in place of the Bilsteins. A mistake I think and didn't solve the issue. I ended up putting Firestone airbags on the front axle. This solved the issue. The stock axle bumpers only had less than an inch of clearance before they struck the axle. The airbags gave me about two inches of clearance so the stock bumpers don't bottom out. They also improved the ride. The front end feels like the ride is being handled by the airbags first and not steel springs. I only use 35-40 psi (100 psi max limit) and they were worth every penny..Just a thought. They also work like quasi sway control when plumbed with individual lines.
