I have 1970 350 olds pulled out of my 50 chevy truck. I started stripping the motor to paint. I can't get the crank pulley off. I removed the 4 small bolts, its loose but won't pull off. do you have to remove the large crank shaft center bolt ? Thanks

 

nope should just wiggle off after the 4 bolts are off

 

maybe tap a thin blade like a paint scraper in between the pulley and balancer face.

 

It is not uncommon for the pulley to require a little, ah, "persuasion" to come off. Also be aware that there is a separate reinforcement plate in front of the pulley that will also come off.