Vibration with a '71 383 cast crank and neutral balance flywheel

[Triple Black 73]

I have an unknown harmonic damper, a '71 383 cast crank (external balanced), and a neutral balance flywheel. The vibration is terrible.

How do I fix it? Or better yet, can I fix it?

I bought a Professional Products PowerForce harmonic damper from Mancini Racing that will be here in a few weeks.

 

[69Bee]

Your problem will be the flywheel. It needs to "OOB" (out of balance) the proper amount for a 383 with a cast crank. Check with Wayne Brewer on one. He should have a refurbished flywheel or a new one and balanced by him for the cast 383 engine.

Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists

 

[Triple Black 73]

Your problem will be the flywheel. It needs to "OOB" (out of balance) the proper amount for a 383 with a cast crank. Check with Wayne Brewer on one. He should have a refurbished flywheel or a new one and balanced by him for the cast 383 engine.

Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists

Dang it, I didn't make myself clear.

I had the vibration before swapping the 727 auto to the TKX manual. I was hoping it would be resolved but it's still there.

I'm starting to think there's nothing I can do about it but pull the 383 and rebuild the original 400 as an internally balanced stroker using my flywheel and damper, which are both neutral balance.

 

[4speed68rt]

Like 69 Bee said, you should talk to Brewers for a solution to your problem. They will know what to do to fix the problem, not just random guessing. There is always a solution. On an external balanced motor you will need the correct harmonic balancer and flywheel, regardless of the transmission.