340 Cast crankshaft and Balance Question

Hi guys,

I have a couple cast cranks for my 340 here are the casting numbers:

3462387
2658393

I’m in the process of buying bellhousing, flywheel, and clutch.

There’s a lot of info out there and some say that there’s no difference between a 318 and a 340 cast crank but some say there is.

I will attach a picture of the balancer and pictures of the casting numbers of these cranks. Depending on which crank I use do I need to balance the engine with the flywheel and all?

All recommendations and help is welcome. Thanks is advance.