I have a 347 in my 66 Falcon. Problem is the engine vibrates from 1500 up. I checked the balancer and it is a 28oz. I replaced it with a rebuilt stock and it still shakes. I checked the weight on the flexplate and it appears to be a 28oz. Doing the math it came out to 28 i should say. I am running out of ideas. The motor mounts are good and it is not misfiring. It is running perfectly. It is driving me nuts. Any suggestions? I haven't turned the torque convertor so see if that helps yet. It is a TCI 3000 stall. I thought it was the exhaust, but had that done too. No change. It is driving me nuts and i really dont want to yank the engine. Any thoughts?

 

Has this always been an issue since the engine was installed? Did the builder state what the rotating assembly was balanced to? Perhaps it's neutral now.

 

Did the stroker supplier say 28/28? Note the discussion here that suggests some are 28/50:

347 Stroker Balance ??? - Ford Mustang Forums : Corral.net Mustang Forum

More discussion regarding balance:

Help with 347 stroker balance question??? Kinda long. - FFCars.com : Factory Five Racing Discussion Forum

More than one forum comment said they are never 28/50, always 28/28 or 50/50.

Lots of folks with questions though. Common answer is take it apart and have a shop balance all the parts.

 

I have no idea what crank is in it.I have come to the conclusion that it is a zero balance crank with a 28oz balancer and 28oz flex plate. The engine has to come out regardless so I am just taking it in to have it balanced. Looks like I just need to buy a flexplate because I can take the weight out of the balancer. I am pissed i didnt notice it when I bought the car.

 

Another gotcha from a previous owner. Sorry dude.