Is this bolt forward or backwards threads

 

It is threaded normally, but you either need to engage the transmission or prevent the motor from moving somehow to break the bolt loose. I would suggest using an impact gun or a long breaker bar or else the motor will start to turn on you. When reinstalling it, be sure to use a little bit of silicone in the keyway.

 

forward or reverse threads

 

It is threaded normally - you have to turn it right to tighten it and left to loosen it.

 

lefty loosy righty tighty

 

An impact gun will defintely help. I would recoomend the 4" Craftsman stubby impact gun. I was able to remove my crank pulley in about 5 minutes without having to remove anything from the radiator.

here's a set of instructions with other tips I learned the hard way when I did mine.

http://www.cherod.com/mustang/HowTo/Pulleys.htm