Been a long time since I did this kind of job, ( last time I ended up pulling the heads and shipping them out to be reworked ) but how difficult would it be to pull all the lifter and put new ones in.

We have at least one, maybe two that are really really bad ( noisy beyond clicking )

Plan on doing a compression test this weekend to determine where the problem is but I figure if I am gonna go through the hassle of replacing one or two, might as well do them all.

 

As you knew, the head must come off to get the lifters out of a 4.0. Be mindful that the cam lobes may be shot as well.