Misfire Under Load At All RPMS

Apr 12, 2020
Hi, so I just recently got my car street tuned (306, Cam, GT40 top end, On3 Turbo kit) and the car developed a misfire. During the tune the car was running fine, no misses or anything, but on my way home, I did a pull going on the freeway and it misfired on the top end under wide open throttle. I'm almost positive it is not the tune, because I went back and we messed with the tune for another 2 hrs to see if the tune was causing the car to misfire. After about 30 miles, the misfire under WOT turned into a misfire at all RPMs under load (15-100% throttle). So far, I've replaced the plugs, the wires are basically new and have boot protectors (500 miles), and swapped the cap and coil with working ones off my parts car. The only things I haven't swapped are wires and rotor. None of those things have impacted the misfire. I'm stumped because the misfire has gradually gotten worse.
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