Hello, i just purchased 87 gt from my neighbor, he had it sitting for 5-6 years and i just got it running yesterday. its completely stock. He said he has had the trans rebuilt, ok now i just took it for my first ride to see how everything was and when i floor the car, it does not downshift at all! Also i took off with the throttle floored and it was shifting at about 2-3k rpms, like i was just cruising. i know absolutely nothing about Transmissions. If anyone has any ideas to help me out i would be really appreciative! thanks in advance!!