Hey bud needing some advice!! I have a 69 roadrunner that i cant figure out vibration. as long as i have throttle pushed, smooth as silk!!! let out of throttle smooth as silk! but when i get in between i have a vibration, the second i get back into the throttle it goes away. had transmission, rear end , and pinion angle all checked. new universal joints put in and still doing the same. Any advice?