Can't Get Rid Of This Miss!!! Help!!!

I have a 94 gt with a 306 crate engine with full by ons. Just incase it might help... Anyways, I started to miss on my #8 cylandar I figured it was tht plug since it has gone out two times before. I also pulled the wire from the distributor cap and it ran the exact same as with it connected. So I replaced all my plugs. Still had a miss. My plug wires were also cracking and were all burnt up and arching on to my headers so I figured it was time to replace those too so I got the ford racing 9mm wires replaced them one by one to make sure I didn't mess up the order. Took it for a test run and it's still missing. Googled the firing order and all that good stuff and it all checked out. Everything was set up right. I even got some injector cleaner and filled up my tank to make sure it wasn't a clogged fuel injector. Still missing..... I am using the same type of plugs as I always have autolite 3924s with a .35 gap. I even took off the dist. Cap and cleaned off everything so make sure there was plenty of fresh metal for good spark. I can't get rid of this miss!!! Can someone please help with any ideas or suggestions??? I miss my car... Feels like I have lost half my hp...

Havnt done a compression test or a leakage test, I guess mainly because of how the miss came about. After some rough runs with the car trying out the turbos I had in it a while back and the nos I currently have in it I started to get a little oil in the #8 cylander and it would foul out the plug after like 3k miles and I would switch it out. No problem car went back to running like a monster. Then I switched to full synthetic mobile 1 (recently) and that's when The problems started happening. Started up with the same ol miss then I did everything I mentioned before. And nothing. It's just hard for me to do these tests on my car cuz I laterally work 13 to 14 hrs a day every day and when I have a day off I just try to stay out of the heat.... I live in south texas and have no connects with a Gerage or lift. I would be concerned with major internal problems if I had been running the car on a track or something but for the past two years I've been usin it as a daily driver. NEVER racing it or pushing any kind of limits, so I don't understand how any kind of major damage would just come About out of no where..... Just installed fiberglass sleeves over the wires to make sure they couldn't possibly be arching off on the my bbks...