trouble with "If'' and "Else if" along with Boolean

Projects Programming
4

CrossRoads:
To start, make all these pin assignments byte instead of int:

//const int loadTime = 100;

const char PacketStart = '~'; << not this one, but the rest
const int portBow_Dir = 2;
const int portBow_PWM = 3;
const int portStern_Dir = 4;
const int portStern_PWM = 5;
const int stbdBow_Dir = 7;
const int stbdBow_PWM = 6;
const int stbdStern_Dir = 8;
const int stbdStern_PWM = 9;
const int vert_Dir = 12;
const int vert_PWM = 10;
const int manip_Dir = 13;
const int manip_PWM = 11;

If I set my pin Callouts from "int" to "byte" how does that change the other part of my coding? Pure curiosity, and want of understanding.

also thanks for the reply.