What is the standard replacement frequency of the factory struts? I have a used 2004 4x4 that has an AAL in the rear since the previous owner towed a 5th wheel. I want to install the HBS 2.5 spacer and not sure about replacing the struts.

 

I also have an 04 4x4 xlt and i have 70k on it now and the rear shocks are in good shape but my front struts are getting worn. my left front is starting to leak a little of bit. so i think i will be spending a few bucks to get them replaced. instead of puttin stocks back in i think im going to go with the Bilstein 5100 Front Leveling Struts. Its kinda expensive $300+ just for the fronts but i think this is better than just the spacers...in my opinion...

http://www.ntwonline.com/0408_FORD_F...RUT_P13613.cfm