Need Advice

[Lycandart]

Alright need a little input. I picked up a early 70's 400 out of a truck that had a 4 speed behind it. Got to lookin at some stuff and it seems as if someone (factory??) has balanced everything. Dont know if the internals were done but the balancer looks like its been balanced and so does the flywheel that came with it. The balancer has a few shallow drill holes in it and the flywheel has been shaved on one side in a spot or two. Well Im runnin an automatic, my question is should I use a stock cast crank converter or an aftermarket one with the original balancer??? And I have read that the 4 speed truck had these parts but not sure how extensive it is.

 

[mopar65]

Alright need a little input. I picked up a early 70's 400 out of a truck that had a 4 speed behind it. Got to lookin at some stuff and it seems as if someone (factory??) has balanced everything. Dont know if the internals were done but the balancer looks like its been balanced and so does the flywheel that came with it. The balancer has a few shallow drill holes in it and the flywheel has been shaved on one side in a spot or two. Well Im runnin an automatic, my question is should I use a stock cast crank converter or an aftermarket one with the original balancer??? And I have read that the 4 speed truck had these parts but not sure how extensive it is.

you can use the cast crank converter but you will have to nock the weights off of it or you can run a stock blancer with a after market converter.I used to have a 71 duster with a 400 4 speed in it.when i blew up my 4 speed i put a 727 in it with a after market converter.thanks Mopar65

 

[rumblefish360]

You must know if it is internally balanced or externally balanced before you proceed.

 

[demon seed]

Before you decide to use anything you have to determine whether your crank is cast iron (probably) or forged (slight chance). Once you determine that then you have to have the dampener and converter matched to the crank. Both are different for either type of crank. Start at the crank and work your way outwards.

 

[Lycandart]

Thanks For the replies... I did a little more research and I might be over thinkin it...and pics help...
First one is balancer in question... Second is stock.. both are cast crank 400's

 

[SGBARRACUDA]

The shape of the balancer tells me it is a cast crank 400 and is externally balanced.

 

[demon seed]

Yes those are dampeners/balancers for a cast crank 400. Have you got a picture of the crank, a person can tell what it is, cast or forged, just by looking at the counter weights. And yes those balancers will fit onto a forged crank (essentially a 383 crank), know a guy who did it and wrecked the engine it vibrated so bad.

 

[mopar65]

you can use the cast crank converter but you will have to nock the weights off of it or you can run a stock blancer with a after market converter.I used to have a 71 duster with a 400 4 speed in it.when i blew up my 4 speed i put a 727 in it with a after market converter.thanks Mopar65

I am sorry i guess i should of read your post better. i thought you said your 400 had a steel crank.my bad and sorry for posting the wrong info. mopar65

 

[Lycandart]

No problem ... I dug around and found a pic of a flywheel that closley resembles mine....But mine has a few more cuts around the edges....but all on the same side as each other