Please note stack types in 5th photo and listed below to order the proper type from drop down menu:
1-Bull Hauler 8mm x 30mm
2-Miter 8mm x 30mm
3-Turnout 8mm x 26mm
4-Straight 8mm x  26mm
 
This item includes on pair of Two Stacks and  m3x8mm hardware to mount.  You will need to drill a hole at the desired location on body. I can also make  them taller or wider at no extra charge but there will be a small lead time. 
These were designed specifically for the betty as it has a shorter cab. 
For scx24 C10 stacks please see other items.