350 SDL general questions

I've had an '82 300 CDT now for several years and can say it's the best car I've ever owned - nothing beats that diesel purr.

Just last week I purchased an '87 350 SDL and have read both good and bad comments about the 350 engine (head warping) I'm looking for suggestions on what I can do to minimize this from occuring. Also need some help understanding some relatively recent repairs this auto has had. I bought the car with 135k, at 116k the following dealer repairs were performed: replaced rear main transmission seal, front transmission pump seal, replaced waterpump & engine belt and tensioner. Replaced leaking intake gasket and intake manifold gasket.

Performed trap oxidizer recall - replaced trap oxidizer and turbo -N/C.

I can't imagine why the turbo would need replacement at 116k, this has me scared. I also notice this vehicle has a catalytic converter which my '82 doesn't. Can anyone explain? I don't really understand all the concern over the trap oxidizer - should I be concerned or did the recall work take care of any problems associated with the trap? If not what else should I do?

Also do all parts for a 300 SDL (i.e. filters etc) work on the 350?

P.S. This is an excellent forum.......I look forward to any advise provided.