I have a 79 f150.. came stock with a 302 and c4 a/t. I have replaced the engine with a 302 (5.0L) from an 87 e150. All went well except now I have a vibration in the engine, appears to be in the rotating assembly. Does it any time, worse as rpms increase. Moving or not. Same trans as before, harmonic balancer from 79 engine. Any help??? Any ideas???