I'll take a guess here and say you drive some kind of Mopar with a 340 engine? If that is true and the heads are OEM type heads, the lifters are not adjustable. The rail that holds all the rockers is all there is. If they are noisey, you may need to replace them. If you have any head work done, make sure they set the valve stem length correctly, especially if any milling is done to the block or heads.
Dipstick? Bent it, twist it, or shorten it?