I've got a 1998 k1500 with a 5.7 vortec. Yesterday out of the blue I cranked the engine and it started tapping bad. After a two to three minutes of running, the noise went away. I know that it is a lifter that making the noise on the driver's bank side. I cranked it again this morning and the same thing. My question is should I replace the lifters or could it be trash in the lifter? I'm leaning towards replacing the lifters since it starts tapping after sitting awhile and then clears up. I priced the lifters and I am definitely suffering from sticker shock ($226.00). Also how hard is it to replace these on this truck?