Caligs300

Well I've turned to the internet for help lol. I recently purchased a 99 gs300. Enjoy the car for 2 weeks, then the radiator popped. I replaced it, then I noticed little puffs of white smoke. I pulled the spark plugs and it was full of coolant. Seem like the head gasket failure is related to the radiator going out. I've replaced the head gasket, now crank no start. I've check for fuel, spark, and compression and the timing marks all match up. I had my brother crank it over again today to show him and i noticed the camshaft spin backward right before it wants to fire up.

Any ideas,
Thanks