*3100/3400 are known for head gasket issues. The early 2.8, 3.1 and 3.4DOHC 60°s are not.
Nah, they're turds too. It's just that most 3800 owners don't like to admit it. Either that, or they've never experienced a car with some actual balls.
It is rather unfortunate that your dad strong-armed you into buying this thing. Given everything that is wrong with it, it's a $1k - $1,500 car at best. Agreed that the best thing you can do at this point is just fix up what you can as cheaply as possible, and drive it till a catastrophic failure happens.
Scotty, are you saying oil can't get into the coolant if the head gasket fails between an oil and coolant passage? Before I bought my previous GTP, I test drove a GTX that looked to have oil in the radiator and coolant reservoir (extremely dark brown to black).