1997 Ford F-150 misfire/power loss

Lifted with 35" tires. Installed 4.10 gears in diffs. Shutters/misfires when idling and lost all power on hills at highway speeds. Kicked a misfire cyl 1 code- I changed the coil pack/wire/plug, still ran rough. Kicked a P0.174 code (lean on bank 1) so I changed MAF sensor, oxy sensors, IAC sensor, PCV-valve and checked for vacuum leaks by spraying flammable parts cleaner on all hoses while @ idle. Now oil temp gauge is up/down, goes into red while motor is cold but running higher RPM's and sticks there, then drops back to normal at idle. Ran can of Seafoam through intake from vacuum on brake booster @ idle to smoke out the carbon buildup in intake, still wants to shutter and give "misfire cyl 1" code. At hard acceleration from idle I can hear what sounds like a valve rattle or maybe the lack of presece of fuel? I have now done the unthinkable and dropped it off at the dealer to get their diagnosis. I was thinking sensors/timing until the oil temp problem. Now I am lost other than a possible bad brainbox. Please help! I know it's high mileage, but all problems can be fixed, right?