So they came from the factory - BB and 727. No fire wall changes so this leads me to believe since there is no engine in the car yet that the trans mount is wrong. Try hooking up the shifter rods and see if they are even close to verify. (I’m assuming they are with the car still?!?) all that stuff should be in the normal location. Maybe more info on what was done to the transmission? Was that an RV drum tail shaft converted to 727 car tail shaft?