It almost feels as if something is sticking inside the transmission, or as if there is not enough fluid in the trans. I know that when an old truck takes some time to shift between gears, its a sign that a rebuild is coming soon, or that the trans fluid is shot/low. I'm bringing it in this weekend to have them check it out. Sometimes it clunks pretty hard when it finally does shift into drive, and that is with my foot on the brake and the car not rolling at all. Other times it feels like it partially engages, and i can see the revs fall slowly, instead of the normal drop rate to low idle. I'll report back asap for all who are interested.