I bought my 97 Sh about 2 weeks ago with 179k miles, and a buddy of mine said i should replace the head gasket because he removed the oil cap while the engine was runing and noticed that there was some very light white smoke coming out.
He also said the it shouldnt be blowing (air not smoke) that much and that its causing me to loose compression... and to have my valves adjusted... :/


should i get a cometic gasket and have the valves tweaked?

 

See if theres oil in the coolant and vice versa

 

and how do i determine if theres oil in the coolant

 

Open your radiator cap!!!!!!

 

I would absolutely make sure it is the head gasket before doing any work.
Do a compression test and more importantly a leak-down test.

In addition, check the coolant to see if its mixed with oil.

What your friend describes sounds like blow-by, where the rings do not seal enough and let combustion pressure leak into the crankcase. This is ususally associated with piston rings or ring lands being broken (from detonation) and not a headgasket problem.