Car idles to high can it be that it needs a good carburetor cleaning even after it in drive idles at 4000 rpm?

1986 olds cutty its on for like 10-15 minutes you can say it warms up and it idles real high you put it in drive still idles you take your foot of the break and it takes off fast so you have to break real violently like if your parallel parking .. what could be the problem tune up?? or timing or a carburetor cleaning or adjusting because its really dirty?? help me out