olds engine balance and manual flywheels

[oldsmobile joe]

i'm in the process of upgrading my 78 olds 260 to a 77 olds 403. the 260 is backed with a factory t50 trans. yes i know it won't survive for long behind the 403. i have plans to fix that delemma. i've been researching flywheels and engine balances but can't find a reliable answer. i know olds engines are externally balanced. will the 260 flywheel be the proper balance for the 403?

 

[Alerch]

Yes it will be, all the later model engines use the same. The 330, early 400 and 425 are the ones that requires the different flex plate/flywheel.