thats exactly the same symptons of my project elite
Give the Idle Control Valve a clean with some carb cleaner, that helped mine a bit. (it was noisey before)
But you can hear the ticking when acclerating at any speed, although can't be heard at a constant speed say 70mph with the cruise on.
My advice, take it to a local exhaust specialist, I took my to ATS and they were very helpful. Popped it on the ramp and confirmed it was the head to my manifold gasket.
Unfortunelty its a right PITA to fix, offically its an engine out job!
But I have been talking with some members here about doing it the easy way, but its still fiddly. Involves getting a very large bar, and popping the engine off its mounts to get better access!