Trojan85

I believe that my timing chain guides are worn but I am not 100% sure. I have a tapping noise when accelerating. The more revs, the worse the sound gets. Does anyone here know how many hours in labour it takes to install a new timing chain kit? I figured that I might as well change the lot rather than just one or 2 parts. The kits £250-£300 but I don't know how long the job takes at around £45ph. Any advice would be much appreciated