I just purchased a car with a heck of a water problem. The previous owner said it had a 350. I pulled the heads to check the head gasket and heads and the gaskets appeared to be alright. I did noticed that the holes for the water didn't quite match up with the gasket. I checked the numbers on the block and on the heads and discovered the heads were for a 305 and the block was a 350. Could this be the cause of the watered down oil? There also was no seal on the front and back of the intake. Thanks in advance!