Anything on exhaust manifolds, motors etc will "burn off" once you are running again. Anytime you work on a motor you can expect a certain amount.
Now..let me say, there is an expected amount as you have these exhaust manifolds that get very hot and oil/grease on them. There is however an unexpected amount of smoke...say like a belt on a pulley that no longer turns because of improper reassembly.
Your smoke sounds very normal. Afterall..you are cooking PB blaster and antiseize at exhaust temperatures. Toss on a steak and you've got dinner.