Ford: ecu, ecm, engine computer, nut bolt, crate motor

Question
ok i have a 85 f150 4x4 5.0 w/a c6 and have replaced every thing from the grill to the bell housing. i dropped in a crate motor from a reliable shop. every sensor, nut, bolt, everything is new but the ecu. a certain car lot around here took the 5 speed out and but in a c6 with a shift kit. now the problem is, she hesitates on take off she is sluggish and don't have the power my last truck had(the same thing just 2 wheel drive). my ? is. is there a difference in the ecu and what one should i have (if you know the part # that would be great) thank you for your time
hit me back this is jack

Answer
what size eng did you take out if it was it a 5.8 or 5.0?and were do you live if you are in high alt. 2000 feet above see level you need ECU # IS E43Z-12A650-ADA below ECU # IS E6TZ-12A650-ZA and there is a difference between auto. Trans and  manual Trans and also firing order.