I am building a 351w for a small hotrod project. I am using budget/junkyard parts as much as possible. I found a crank pulley I want to use (because it's a 3 groove) and the part number is D3AE 6312 EA

Do the pulleys themselves have anything to do with the engine balance? Can I use a 302 pulley (not balancer) on a 351w and vice versa.

Even if they were from a 302, the D3 part number means they're from an early 302 with a 28oz imbalance anyways right?

The reason I ask is the crank pulley is a large iron one and not a stamped steel one like some other Ford engines.

 

If it's 28 oz. i think it will work.Some 302s are 50oz. some 28 oz. I'v never worked on a 351w,so you better wait for somebody else to come by.

 

wrong, it means it was designed for an engine in that year.

The suffixes are what determines what year it is fromn

That is a stamping or engineering number not really a part number.

Unless it is a combo harmonic balancer/Pulleys then you can use it on anything

The cast iron piece should have counter weights on it to keep it run true

 

Thanks for the info. It is seperate from the balancer for sure and it doesn't have counter weights but there are drill holes that are for balance I assume on the rear face of the pulley

 

That pulley was used on 76-77 302's and 351's for numerous Ford Cars

 

I believe the pulley's have nothing to do with balance.
The 351W and earlier 302 are 28oz externally balanaced engines. Balanced externally with the Flywheel and harmonic balancer. Note the balancer and the flywheel can only be mounted in one position. Keyway on the balancer and the bolt pattern on the flywheel only allow for one position for mounting.
Now the pulley on the other hand has four holes and can be mounted in any of the 4 positions.