1985 ford mustang gt a reliable and smart purchase for a teenager?

The 1985 ford mustang has been my dream car for the past 3 years! Now i'm 17, i have a job where i can actually afford a car payment, well my father pays the original price tag and i pay everything as i go in a fixed monthly rate atop of the insurance so i'm actually buying the car. And i've been looking at several of these 85 gt s, the one i'm looking at right now is 4 grand. With a rebuilt engine and an after market carb. And i was wondering if this would be a smart purchase for me? How much would the insurance run me? Currently i pay 100 dollars for a 2003 civic lx. And basic things i would have to watch out for while owning this vehicle? And i understand that with older cars do come certain issues but i'm willing to deal with those as they come.

No 30 year old car is "reliable".

A 1985 anything won't be a reliable car. But if you go into it knowing that fact then the money you spend on repairs won't be a surprise.

Expect the insurance to be double what you pay for a Honda Civic.

Such an old car will cost you lots of money just to keep it repaired and running, day to day. It's NOT a good choice as a first car for a teen who has little money to keep it running. Simply finding parts will be a big problem.