water in the crankcase and I'm at a loss as to why. advice??

[Guest zblue240]

I was checking the oil on my 71 240Z today and found a nice foamy mess on my dipstick. Yipee. I pulled off the head to replace the gasket and couldn't find a breach anywhere. There is no water in the cylinders though. Are there any other weak points that could let water through into the crankcase? Does the head need to be stripped to do a pressure test? Any way to check the block for cracks without tearing it out? Thanks for any help...Ryan