The correct shims between the spindle and the knuckle for Camber. Is it loose or is it sticking from side to side and you have to correct constantly........To tight of Ball Joints can cause that.
My son used a product on my Chevy II that was called Shootz on the rockers....I think? Kind of rubberized looking and feeling. Went on clear and he painted right over it. It has been on the car for 28 years and no chipping or peeling........YMMV
I have a 66 Chevy II with a .030 327 and it is an older block(65). I had the old tube that bolted into the rear of the block and used that to plug the hole with a cap on the tube that had the hose to the pcv......no leaks......yet.......6+ years