340 engine balancing questions

[matt63]

I am trying to sort a few things out here. First of all, did the 340 have different flywheels depending on the whether the crankshaft was forged or cast? I know that the dampners were different.   Secondly, which flywheel is mine- casting#s 2264598?  Can I use this for an externally balanced 340 build-up? (I may be using a 4" stroker crank and the machine shop will balance the rotating assembly)

I am planning the 340 rebuild this winter as this will be the last item on my Cuda's restoration list as everything else is nearly done.  Currently I have a std bore 1973 340.  It has a cast crank and came with the proper harmonic dampner/balancer.  I am not sure whether the flywheel that came with the engine is a 1973 340 item or not.  It doesn't look like it has any "unbalance" built into it like the dampner does.  It does have 6 unequally spaced crankshaft holes.  It is in good shape so I would like to use it for a 340 stroker build-up.  I would like to use the MP 4 inch stroker cast crank which is suited to external balancing.  Converting to internal balancing is expensive and I am told is not required for street/strip engines.  If I wanted to go to internal balancing I think a forged crankshaft would only be marginally more expensive.  Any ideas? ::

[Chryco Psycho]

the flywheel you have is correct sort of , all 340 flywheel used that casting but the external balanced engines had holes drilled in the rear of the flywheel for balancing , assuming you are having the whole engine built you can have the crank ,rods, pistons, flywheel & damper balanced so there is no problems  at that time

[matt63]

Yes, thanks Chryco.   There is only one 1/2" hole in the back of the flywheel which should be enough to neutral balance the flywheel only.  I am guessing that more mass would have to be removed for external balancing??  It sounds like either way the machine shop should be able to work with it as balancing of the whole rotating assembly is the plan.
 

[Chryco Psycho]

you can use a forged 318 crank & have it balanced , they are relatively cheap to get