noise on engine asap

i was on here the other day to find out my noise ok the ticking only i mean only happens when i hit 2800 to 3200 rpms and when i let of the gas or drive slow when i drive fast it comes back why is that my auto guy told me today to replace cam shaft and rocker arms said if i replace rocker arms i should replace cam to its a 88 2.2 b2200 need help asap i want to fix this asap