What poppers to use on 91 D-50?

Hey guys, my buddy actually has a 91 mitz mighty max, but its pretty much the same truck. Anyways, inside the door it is so narrow that we cant find any sort of popper to fit inside. We used door lock actuators but those arent working as well as we expected so now he wants to put poppers in it. Does anyone know of a kit for these narrow doors to use? Autoloc, spal, anything. Thanks in advance!