they were all 2 door up to, and including 66, then in the 67 - 72, they were 3 door, and 73 on up are all 5 door.
Even though that's how they were all made, you'd be amazed at how many 'rare' 3 door burbs, and 'rare' 2 door burbs we hear about. Got a guy with an old rusted out POS burb, a 69 with a 396... he will NOT come off of it becouse of that rare door thing.