Body shop question about swapping brake lights.

I have a 99 CVP71. That year Ford rear signal light was that small amber square at the bottom of the brake light. I think that the signal light can be seen better on the newer cars since they put the turn sign in with the brake light. Possible with a double lamp bulb. Will a newer set of brake lights fit my car? Will it fit but need some adjusting since I don't want to change the wiring harnes. In other words, will I have to put a hole in the brake light for the turn signal lamp to go in?