[DoubleD]

If I had the wrong flexplate would the engine vibrate a little or would it rattle your teeth loose? I have a 289 that has a engine vibration that's related to engine speed, just a slight buzz in the steering wheel at certin speeds.

Thanks DD

[cobra350]

i think it could make it shake a little

[RemRem123]

yes, it could cause a vibration. what transmission are you running and has it been swapped out?
Ford switched from 28 oz imbalance to 50 oz and running a 28 oz harmonic balancer and a 50 oz flexplate would cause quite a vibration, the higher the engine speed to worse the vibration.
This is a serious issue if that is the case, but it could be other things than your flexplate; engine not balanced, loose bolts (in flexplate, etc.),

[mwillis]

Are you sure it's engine speed related or car speed related? I had a vibration about a year ago that was cured by replacing the tranny mount, believe it or not. It's cheap and not too hard to replace. My vibration seemed to be between 55-65 mph. I never would have thought the mount was the cause. It just gets old and soaked with oil, and compresses to the point that it's metal resting on metal, with no rubber isolation anymore.
Hope this helps.
Mike