Start & Finish Position
A wide-stance Press-Up will place more emphasis on your chest, rather than your triceps. Having a narrower-grip, achieving the reverse. Why not perform a multi-set of varying grip Press-Ups.
Muscle worked during the Wide-Grip Press-Ups:
Primary Muscles: Pectoralis Major - Mid Sternal Fibres.
Secondary Muscles: Anterior Deltoids, Triceps, Serratus Anterior, Anconeus.
Stabilizing Muscles: Lateral Deltoids, Rectus Addominis, Transversus Abdominis, Forearm Flexors...