new shocks ???
 

how do you know when it is time to replace the shocks,

I replaced the front shocks about 6 years ago with just a standard set of gas shocks, and installed a set of Gabriel air shocks on the rear,

wondering if it is time to replace the fronts again, when I bought the truck 6 years ago, the old ones I took off did not even move they where seized up

Re: new shocks ???
 

Is the front really 'bouncy'? Meaning does it continue to oscillate after you go over a bump? If so, it's definitely time. If you care to take one off, set on end on the ground and push down on it - it should be pretty hard to push down and should come back up smoothly and fairly quick. If it pushes in really easy and/or stays in after you push it, it's done. Is there any oil around the piston or seal?

I'm sure others will chime in with more/better experience, this is just my redneck shadetree mechanic way of checking.