swaping fly wheels

[41husk]

I have a 1972 340 cast crank motor.  It was bolted to a 727.  I am swaping to a 4spd.  Can I take the flywheel of the 318 that was bolted to a 3spd and bolt it on?  Do I need to find an externaly ballanced fly wheel or will the one from the 318 work without ballancing?  I have never done a swap before any help will be appreciated.

[Chryco Psycho]

the 318 will bolt on to the 340 but it will need to be balanced to work , balancing involves drilling holes in he rear face of the flywheel , there is a guide in the Mopar Performance Engine manual

[41husk]

Thanks! as always you have been a great help!!!!  I am sure I will have more questions as I go.  I dropped the 340 off at the machine shop and will get it back as aready to go short block in about 6 weeks.

[John_Kunkel]

The diagram below shows how to external balance the flywheel for a cast crank.

[Cooter]

John, Got one of them fancy diagrams for balancing a Steel Crank 318/340 Flywheel (10.5") to a 360? I know it has something to do with the three big holes on one side.

[41husk]

Thank You very much.  You guys are great!!!

[John_Kunkel]

For the 360 LA

[Cooter]

Most excellent. Thanks John.