What would cause a 91 Aero star to feel like the brakes are being applied when placed in gear except reverse.?

I cannot drive my van because it feels like the brakes are being applied when placed in gear except reverse .The gears engage it feels like the brakes are applied after a few feet. What can this possibly be? I've been told It is the calipers and I have been told it is the tranmission which is more likely?