I just read on this sight that the 351w and 302 engines use different balanced flywheels and now I am a little confused. Last summer I swapped a 95 351w into my 94 F-150 and reused my 302 flywheel for my 5-speed tranny. The truck runs perfect with no vibration or any other problems. What effects is the wrong flywheel going to have on my engine?

 

If the imbalance was wrong for it, it would have a severe vibration, shaking actually. The pre 82 302 used the same imbalance flywheel as the 351W's. All 351W's use the 28 oz/in flywheel/flexplate. The 82-up 302/5.0 uses a 50 oz/in.