400 Crank and Rod Question. Interchangeability

I've got a '69 GS400 that decided to spit a rod when under the care of the previous owner. The block is being sleeved and is salvageable, but the crank and 4 of the 8 rods are toast. I've been told that the crank and rods are the same for 400's, 430's, and 455's. Is this true?

Thanks in advance.

Allan

 

They are. If you have a manual trans, you'll have to make sure the new crank is fitted with a pilot bearing.

Devon

 

Thanks.
It's an Auto so not an issue there.

Allan

 

Crank will be the same basic design, perhaps different casting numbers. Most important will be the factory balance which would vary with bore diameter/piston weight.

Rods should be just-plain-interchangeable although it would be smart to match the weights there as well.

The factory individual-engine-balance weight pins in the damper, and the punched-holes on the flexplate will almost certainly be incorrect for the new parts.

AFTERMARKET BALANCE JOB STRONGLY RECOMMENDED and not easy on Buick engines.

 

Thanks.