replace door with window ( header needed?)

Hi everyone,

Scenario - Besser brick house, single story, low ceiling, flat roof, slab floor.
I want to remove a door + jamb ( the jamb is metal ) and install a window into the opening.
Currently, above the door opening, there is half a besser brick (in height) and then another besser brick on top of that and then the top plate. There is no header above the doorway. So 1 + 1/2 bricks above the doorway.
There is a window close beside this doorway and to make the new window the same height I need to remove the 1/2 brick row of bricks and leave the top row of full brick intact. And then lay a row of full bricks on the floor.
The window i wish to install is Vic Ash hardwood and approximately 860 wide. It has quite thick vertical sides/reveals and also a center mullion running up the middle splitting the window into two seperate panes (each approx 410 wide) Very heavy and plenty of strength.
So im after your opinions on wether removing the 1/2 row will weaken the top row substantially leading me to have to remove them and put a header in? Or do you think as i do that the top row will remain keyed in and the strength of the window plenty enough.Thanks

Is the opening when you remove the door the width that is required for the window. If it is you wont be disturbing the wall too much. With only one course above the window if it moves too much will it be to repair be quicker than saving the blocks. If I really wanted to save the course you can support it, by drilling holes it the morter under the top course and push steel rods through. On each end of the rod support them with a bearer and props.

Thanks mate.
Handy option to have.