Hey Yal, nearly got it all figured out. I was trying to make some of the walls more rectangular and less squared. I used the below to do so in the draw event and it looks perfect. However, the collision box is still the full square. I made sure to also change the tops and bottoms.
draw_set_color(c_gray)
d3d_draw_floor(x ,y+32 , zbottom+0.01,x + sprite_width,y + sprite_height,zbottom+0.01,my_fex,image_xscale,image_yscale)//Floor
draw_set_color(c_white)
d3d_draw_floor(x ,y+32, ztop-0.01 ,x + sprite_width,y + sprite_height,ztop-0.01,my_fex,image_xscale,image_yscale)//Ceiling
d3d_draw_wall(x ,y+32 ,zbottom+0.01,x + sprite_width,y+32 ,ztop-0.01,my_wex,image_xscale,1)//Back wall
d3d_draw_wall(x ,y + sprite_height,zbottom+0.01,x ,y+32,ztop-0.01,my_wex,image_yscale,1)//Left
d3d_draw_wall(x + sprite_width,y+32,zbottom+0.01,x + sprite_width,y + sprite_height,ztop-0.01,my_wex,image_yscale,1)//Right
d3d_draw_wall(x + sprite_width ,y + sprite_height,zbottom+0.01,x,y + sprite_height,ztop-0.01,my_wex,image_xscale,1)//Front?