Personally, I would never run a bb mopar head with the crack under the exhaust ports that had been repaired that way, in a racing situation.

I've had two motors on the dyno that developed cracks there.
They didn't leak a drop until you started applying a load and making power.......when the head is trying to get lifted off the block, that crack opens up and it's like you turned on a garden hose, with coolant spraying out.
Back out of the throttle.........the flow just stops.

After seeing it first hand on two occasions.........I don't wanna be the guy behind the wheel when it lets go and gets under the tires.