You might want to replace the radiator cap.
What did the old gaskets look like? What did you find? Did you tap the threads in the block? Did you put thread sealer on the lower bolt threads? Using RTV on the head bolt threads, or failing to tap the threads in the block where the head bolts go, can give a false torque reading. Also, if it does happen again, be sure to have the heads surfaced.
Take care,
~Chris