The clicking is prob worn rocker arms or possible worn cam lobes, hopefully the later.

*Could* possibly be a worn a bad exhaust manifold.

Here are some old threads on the subject:
Ticking 1

Ticking 2

My '91 SEL ticks when cold and warm. Have not yet diagnosed the problem. The chain/guides needs to be changed within a year, so will have it looked at then -- hopefully the rocker arms.