balanced 340

yellow rose said
It depends on how the balance job was done.

If the guy who did it made corrections on the damper than it will change the balance. Also, you are making the assumption that the OE damper was zero balance, the new damper is zero balance and no corrections were made on the OE damper.

I see your point... but if the 340 in question uses a stock balancer for that year, then IMHO it is a pretty high % probability assumption that the OEM balancer was not touched. The unbalanced damper used in later 340's is pretty obviously imbalanced.

Maybe the OP can help us with a few more details.

General Disarray said
Isn't your 340 internally balanced? The 360 is externally balanced, I believe. Be careful you don't select the wrong harmonic balancer.

You are correct for the stock '71 internals.