background story....went to the drag strip and raced my car, next day car starts messing up, open up the distributor and rotor button screw is out, put it back in and everything's fine till car starts stuttering badly a few days later...turns out sparkplug wires are working themselves out

alright here's what's happening currently...seems like I made the problem worse...Saturday I drove almost 200 miles without a problem until I went and chased down a friend on the highway...at around 125mph it started to stutter (I should also not that the day after coming from the 1/8 mile drag strip I raced someone and as I was approaching higher speeds the problem began)...so I slowed and it kinda sorta went away...well the problem persisted, to where I had to push down the wires once twice a day, when I got to work and when I got home...it was always the first 2 and sometimes the 3rd spark plug wires that came out...so last night I take out all the spark plugs and clean them up as well as the inside of the spark plug wires...well apparently this made the situation a lot worse...5 times on the way to work (12 miles) I had to pull over and push down the plugs b/c the car was near stalling...once all 4 came out

now my question to you is what could be causing this? btw the engine is a B16b with about 60k miles and I'm using NGK Iridium spark plugs with some wires I got from Autozone...I've had these on my car since November and made 9 runs on the 1/8 mile dragstrip on March 5th, on March 6th is when the problems began