70 340 block/ 73 crank and balancer

Well, I am a bit confused myself, now. I went and dug out my 340 cast crank damper, and a 340 steel crank damper. I took a mid 70s AC pulley off a 318 A body, bolted right to both, and the spacing was the same. The cask crank balancer IS slightly thicker, but that doesn't effect the pulley. One bolt hole needs slotted, but the pulley was spaced exactly the same on either balancer. I think the OP needs to post a pic of what he is trying to put together. Maybe his balancer isn't fully seated on the crankshaft?