Ford Repair: Missing mostly under power., distributer cap, inner fender

Question
I have a 89 Ford F150, 302 V8, automatic 4 speed trans with 64 thousand miles, that misses when I give it the power.  I have changed Spark plugs with .044 gap, and plug wires,(was very carefull to get it right),and  Distributer Cap and Rotor. I still get a miss under power. I even suspected water in the fuel or dirty injectors. I put in HEET for the water removal and injecter cleaner. It idles good. The only thing to change now would be the Ignition coil and/or the Ignition Module which is mounted outside the distributor. Possibly the ignition selonoid which is mounted on the right inner fender panel. Do these items that were not replaced yet, cause the missing under power? What do you suggest. I about ready to give up.  

Answer
My suggestion, would have the vehicle run on a diagnostic computer at your local garage. Dont assume one or more sensors are bad, this will run you into big money.. I have seen to many people replace this and that and find out later that wasnt the problem... Thanks..