Why not build the foundation for an big chest while building the muscle mass of the pec's? That would be building the basic structure of the rib box. The 20 rep breathing squat (3 breaths at the start, winding up with 6 to 8 approaching the 20th rep), followed by pullovers might be a good start. Also an excellent way to boost up the metabolism to increase muscular weight gains. Old school can build exceptional bodies even today.
The cartilage between the ribs and the center of the breast bone is made up of elastic tissue that becomes hard and set around 24 to 26 years old in the average male. You will never make the bones of the rib box grow but the elastic tissue can expand between the ribs and the breast bone. Which in turn produces a deep and broader chest. Even older trainee's can experience a lifting affect to the rib box due to the attachments around the rib box. What I have read about and seen, a 2 to 3 inch gain in chest size can be experienced. The basic program is breathing squats/pullover (advised to do 1 set only..some have done 2 but never more). Than BP and BB rows. That is the whole program, twice to 3 times a week.
If not up to that style brutal training and wish to avoid squatting like the plague (where has the training with serious intent gone, I wonder), than might do Bent arm pullovers & press, DB Inclines and dips. Usually 2 to 3 sets each....no more. The Bent Arm Pullover, by it's nature, can also have an expanding affect on the cartilage around the rib box. Again, if the cartilage is still in a somewhat plastic state. Either bent arm or straight, the pullover can build the lat's and triceps very well. If your 18 or 60, the time spent with any form of pullovers can be it's own reward. Good Luck.