hi im having some trouble with my 91 z28 tpi 350CI, periodically when i am driving and accelerating at 3/4 to WOT it will start jerking, the rpm gague will go crazy all over the place. all of this only happens over 2000rpms. when i am driving down the road and cruising up tp speed keeping my rpms under 2000-2500 there is no issue, no problem idling and in park i can rev out to redline with generally no issues. i have replaced the wires with accel 8.8 ferro. the cap and rotar with accel, and an msd street fire coil. all to try and fix this issue, i have a minor exhaust leak on my driverside header that is before the o2 sensor and my knock sensor right above my oil dipstick i just came to find out is out and was on the header. but that knock sensor hasnt been installed for a while what do you suggest i do to fix the issues that i an encountering. thank you very much i hope i gave enough info