I have a 1969 bbc that i got for free from a freind all I had to do was his landscaping. The motor is majorly board out I pulled the heads pistons and rods and there was a craked piston can you anyone tell me how this happend. I have been told it could be from to much compresion. It has some huggge dome pistons. Can some one help me should I just throw new piston in it and fire it up or completly rebuild the puppy.