Engine Balancing Q?
 

I have a '69 K20 with a 350 from an '84. I have a hodge podge of pulleys and accessories, so I am updating everthing. When I removed the crank pulley it was a heavy iron pulley with holes drilled in it for balancing. Everthing I've ever seen is just a harmonic balancer with a stamped steel pulley. My harmonic balancer also seems narrower than I remembered.

Do I have to Install a larger/thicker balancer?

Do I have to use the iron pulley or is it ok to install the new stamped steel pulley?

Some SB 350's came with a 6in. balancer and some with a 8 in. If the engine was balanced from a machine shop they might have balanced the front pully also. If not you should not have a problem with just changing the pulley. You want to stay with the correct balancer though.

If the engine was balanced with the iron pulley on, What problems will I create if I throw it away and install the stamped pulley?