340 Crankshafts

[randy73]

I can only find 3.31 forged for internally balanced engines, since I am basically replacing the whole bottom end (pistons, rods & crank). The only think I need to do is replace he dampner and fly wheel and then have the rotating assembly balanced, correct?

[A383Wing]

I thought 340's were all internally balanced? The 360 is the odd-ball that's externally balanced

[randy73]

No, 72-73 340's are external.

I believe some 318's are and cast crank 383's also.

[fy469rtse]

Yep that's the difference guy's
Cast and steel , forged cranks , internally and cast externally balanced,

[A383Wing]

if your 340 is externally balanced, then there may be a weight on the converter as well that needs to be removed?

[John_Kunkel]

318's were all internally balanced, cast or forged.

Only the late '72 340 was cast, early was still forged. April 11 was the introduction date for the cast crank.

[randy73]

Can someone please answer my question?

I am trying to order the parts asap. 

A383, I just put a 46RH in and have a flex plate that is weighted and one that is not.

[BSB67]

Can someone please answer my question?

I am trying to order the parts asap. 

A383, I just put a 46RH in and have a flex plate that is weighted and one that is not.

Wow.  We were to get that from your original post? Really?  Frankly, I never understood your original post, and even less now. 

What is an A383?

If the rotating assy is, or will be internally balanced, then you can use neutral balanced damper and flex plate, or flywheel, what ever you are using.

[randy73]

Can someone please answer my question?

I am trying to order the parts asap.  

A383, I just put a 46RH in and have a flex plate that is weighted and one that is not.

What is an A383?

Short for A383WING, as in the user A383WING!!

Yes, car is 73, so it is externally balanced, it was only a MINOR detail. 

[randy73]

I have a 73 340 (externally balanced) and am looking for a stock forged crankshaft (i.e. stock stroke 3.31") and I only see these cranks for internally balanced engines.

So to put a internally balanced crank in my 340, I need to change the dampner and the flywheel?

Sorry, I have to stop posting after a night out.   

[John_Kunkel]

Yes. Once you install a forged crank, all of which were internally balanced, you need to change to a neutral balanced damper and flywheel.

[randy73]

Thank you!