Hello all. I am new to the forum but have been an avid reader. I purchased a 1998 RR 4.0SE 3 years ago and love my truck but have had to make a major repair every year. It currently has 93,000 miles and I had to get the air suspension converted and the blender motors replaced (my HVAC diagnostic light is still on

). Now I have a few questions that I need some expert assitance with:
1. I am having crazy front end vibration issues. If I hit a pot hole or a groove in the road my front end and steering wheel shakes uncontrollably for a few seconds. It eventually stops but is very scary and unsafe. The dealership says I need 4 shocks and a steering stabilizer and may need a drive line transfer case. HELP!!!
2. My engine valve/lifter has been ticking and a mechanic told me that I needed to flush out the engine. I tried Sea Foam but that didn't do a damn thing. I don't know if flushing out the engine would harm it or be detrimental to my RR's performance.
Any advice someone can lend me would be appreciated. I will upload some pics soon!