hey all, i'm new here. I have an 89 E350 14' cube van. it's a one ton with dual wheels. my question, or issue rather, has to do with the transmission. it's an auto, but it seems that it's only a 3 speed. it seems that at highway speed the rpm's are waaay too high, and seems like it should shift.
basically i wanna know if I should have overdrive. could anyone tell me how i might identify my specific model of transmission, and if it should have a 3 + O, or just the 3 speed?

i do have some pics of under the console. i'm kinda new to the econoline, but not new to the ford buisness.