It's been a long time since I tore down a  YBlock.  I pulled the engine out of my 55 TBird.  I have it on the stand for disassembly.  I pulled out my trusty 40 year old harmonic balancer puller and to my surprise there are no threaded holes in the end of the balancer.  Back in the day I probably used a sledge hammer.  How the heck do you pull these things off?