so i think i fixed the problem! i picked up a Haynes manual today and discovered that what i thought was cylinder 8 was actually cylinder 4 which is probably why i was getting the same codes after i switched the coil packs and fuel injectors on the passenger side. so today i installed new Motorcraft plugs on cylinders 5,6,7 & 8 (all the driver side plugs), replaced the COP's on the same cylinders with the HD ones and i also swapped the #8 injector with the #1 injector just to see if the "misfire" code would jump to cylinder #1.
well i used my Xcal2 to erase the old codes, set the PCM back to factory settings and fired it up...it's idling much better now and it seemed to run fine when i took it for a test drive. no new codes popped up when i plugged my Xcal2 back in and the engine light remained off. i inspected the COP on cyclinder 8 and it appears ok... all the plugs looked the same. i'm guessing the COP in 8 just took a crap
btw this was the first time i tried tackling the spark plugs on my own and i was pretty apprehensive about the whole ordeal. i discovered that moving the power steering reservoir, mounting plate & fuel rails out of the way (plus some key vaccum hoses) provides much better access to the COP's, plugs and injectors. i couldn't get my torque wrench in there so i just torqued the plugs by hand...i suppose time will tell if i tightened them properly. i'm just stoked she's up and runnin' again and i didn't have to take it to a mechanic