Hey Jack,
Start with the timing. Post to all of us that you have checked it and it is where it should be, then we can focus on cooling/fans/etc. My cobra just ran hot, real hot, by being off in timing, and once it gets hot and starts burping water, you also introduce air, and it just gets worse. Check the timing and rule it out right away. Sorry I didn't see this post sooner (work is nuts), but I also just experienced this one two weeks ago....
Now I just need to helo-coil the darn distributor hold down bolt threads which may have caused the above
Take care.