1978 model yr weakness'
 

Looking to buy a 1978 SC but would like to know what the problem areas are for this particular Calif. yr model. I understand even though they are "bulletproof" they do have problems such as broken studs. Also did they still have the thermal reactors for Calif. smog control?

No SC's came with thermal reactors. It came with a smog pump, EGR and 2 way cat converter.

check for broken head studs, tensioner upgrade, do a leakdown and comp test. A good ppi from someone knowledgable about porsches should check most of the critical areas. also check for rust. And keep in mind, it's a 29 year old car, it will need work.