Opinions on my problem, inconsistant power

Ok some back-story to my problem. last week a spark-plug backed out after 15,000 miles on them and in the process of backing out it took all the threads with it...Got it helicoiled. Thought that was the end of engine trouble. NOPE! after driving it i couldnt tell the difference..little bit off top end according to a G-tech(never really accurate anyways) Running wise it runs ok but if i get on it at wot it bogs down about 4500. and then starts knocking and idling very rough. Throws no codes. Turn it off, restart and runs fine and dandy. Wot it again and it goes through the power band fine and dandy. no knocks no sputtering no problems. I changed the fuel filter. Compression test was ok. all plugs are good too. any insight to what this may be would be great. I am trying to exhaust all options before i tear the motor down and flat out replace the head assembly.

bump bump

As far as the helicoil goes ford put a tsb out saying the proper fix to a stripped out spark plug thread is a new head. As far as creating more problems i think that depends on if the helicoil is installed right. Now as far as the shavings that may fall down into the chamber those can get stuck in bad places such as along the piston ring. As far as my problem with power, it hasn't bogged down again since saturday..and believe me i have been running it hard to get it too and it hasn't so i am thinking it was the fuel filter cutting out. Makes sense considering the car sat all winter and had some pretty nasty gas that got ran through it. sediment blockage. grr. thank you for your time.

15815
Do not repair spark plug port threads in aluminum cylinder heads-
Unapproved usage of helicoil for serice
Some engines equipped with aluminum cylinder heads may exhibit spark plug port(s) with stripped or missing threads, "Do not" service stripped or missing spark plug port threads by using "helicoil" or "tapersert" repair kits. It is likely that additonal engine damage or engine failure will occur after an unsuccesful atttempt to service the cylinder head spark plug reports with "helicoil" or taperset. The only authorized service procedure is to replace the cylinder the cylinder head assembly when spark plug port threads are damaged is to replace the cylinder head assembly when spark plug port threads are damaged and in need of service, refer, to the pertinent workshop manual (section 303-1) for cylinder head removal and installation procedures. Note: When servicing spark plugs for any reason , do not use air or powertools and take care to ensure that spark plyugs to not crossthread.