hey i have an 86 crustang with a 347 stroker kit. i finished my build and the car is running strong, but i was geting a vibration if i floor it and would start around 3500rpm. i unfortunetly forgot to replace old flywheel to a 28 oz flywheel. i didn't beat on the car at all after. also i have the correct harmonic balancer for the kit. im just wondering if that did any damage to the motor, and wat are good options on new.