Manifold?

 

mabey so check near back around seal for leaks on a warm day light white smoke will smell like anitfrezz comeing from the pipes is sign too ,dont know where you live ,/ have you dont compression test

 

Rust in the system should not cause any major problems other then a water pump failing a little sooner then normal and freeze plug only lasting 5-6 years. You can even add rust inhibitor and water pump lubricator to the coolant. As long as the rust is not blocking any passages the system should work fine. If you are having issues with the car getting hot I would forget the rust and look at the system as if it was just a car getting hot.

1995 Did have some 3800 but they are pretty rare, Just under 5000 (4%) and They where mostly California cars.