I have a 1959 Morris Minor--I was driving from Southern Oregon, USA to Portland, Oregon (about 300 miles). Apart from needing the carburetor cleaned and the points adjusted in the middle of the trip, everything went fine. That is, until I got within a mile of where I was headed. Going up a short incline the engine lost all power--sounded like it was running on maybe two cylinders. When I pulled over, the car was not steaming (overheating), and had oil and coolant in it. When I tried to start her up again, she started spewing water down below somewhere (all hoses look good) and built up a lot of presser in the radiator. When I took off the radiator cap coolant spewed out--not hot, but like it was under pressure.
My first thought was the head gasket, but I am not so sure. I know it is hard to diagnose without being near the car, but any ideas? I have changed the head gasket before (two years ago), so I can handle that. Anything else, I am not so sure

Thanks--
Sean Wilcox