72 340

[345Dart]

anyone know if you need a balance weight on the convertor (like a 360) for a 72-340 cast crank with correct dampner?
TFY

[John Kunkel]

Yes, the '72-'73 340's with cast crank take a small weight, 5/8" X 7/8" X 3/16" thick.

[345Dart]

Thanks John - do you know @ what location on the convertor? or can that only be determined by a balance?

[fastback340]

Some 72 340s had forged cranks and dont need the balanced converter.

[rumblefish360]

I was under the impresion that the '73 - 340 was the only year for an external (sp) balance. The only 340 to get that treatment.

[perfmachst]

hello, late 72 ,340,s got cast cranks. NHRA allows the use of steel cranks in 72 340,s. 73 ,340,s use cast cranks.

[Twisted360]

If it is a cast crank then you need both the offset convertor and balancer. To make life easier just use the B&M offset flex plate and you wont need weights on the convertor. Make sure you specify what tranny.

[rumblefish360]

To make life easier just use the B&M offset flex plate and you wont need weights on the convertor.

Are you sure. The reason I ask is because the balance is not the same as a 360.

[jd-indy]

Mopar performance sells a weight kit that comes with weights for almost all engines 340-440. Templates are included. The 340 takes two smaller than 360 weights L=.88 W=.62 Thickness=.177 I had a 73 340 years ago and I remember some type of attachment ring on the harmonic balancer that said for use with cast crank only.

[Twisted360]

Rumblefish I think your right. Now that I think of it I do not recall a B&M flexplate for a cast 340. Call B&M I guess.

[345Dart]

To all who replied - the info is most helpfull. - cast 340 is a little bit of an oddity, but usable.
thank you

[John Kunkel]

B&M does make a flex plate for the cast crank 340, their number is either 10234 for a 904 or 10235 for a 727.

[hotrod7043]

Only Year Cast crank340 was a 1973 , 72s were all steel.