Your reply is indicative that you are new to these cars and motors? That is not the knock sensor that is part of the alternator harness and that is also a factory block ground at that point as well. These cars do not have a knock sensor, they only have a Cylinder Head Temp sensor back towards the 5th cylinder. Also when you apply Cooper Spray gasket you apply it to the head gasket while it is hanging and you spray it liberally, let it dry for a moment until it becomes tacky and then install it. The picture clearly shows weeping on the block.
Agreed, I PM'd him and he did not want to give any details in his response to me. The $15K might be worth it, but he needs to give a potential buyer some level of confidence that the car is worth it with a build sheet and dyno sheet. The car is really beat-up and a true drag car. The motor is where the money is at. $15K would be hard to justify!
Yasin