i have a ticking that sounds like its coming from the heads does anyone know the problem there is also a power loss. could it be the hydraulic lifters and can they be changed with the heads in place.

 

The ticking could be spark jumping, collapsed lifter(s), broken valve spring among other things all of which could cause a loss of power. The entire intake manifold assys need to be removed to change the lifters, but not usually the heads. It gets a little complicated changing just lifters without checking the cam(s). Best to narrow down the problem before jumping to conclusions unless you have already done that. If I asked if the oil level was checked, please, don't get angry with me.