66 Burb cooling system questions

[1966burb]

I am finally back on the BURB project. I purchased it a couple years and it came with a 350 engine with unknown history. I changed the water pump, thermostat, all the hoses. Had the radiator boiled out. ( the guy said he has never seen such a nice clean 66 rad) On one of my first short trips out I came back and as I pulled into my shop the top radiator hose blew off. Thinking I maybe had compression in the cooling system I took it to a shop and they did the sniff test in the rad. Everything appeared good. Now, when I drive it even for a short distance the top radiator hose gets rock hard and I am afraid it may blow off. I have taken some 3 hour trips towing my small trailer and had to problems, but I don't trust it. Any ideas??? About ready to rebuild the original 327 and get that put back in.

[jonzcustomshop]

even though it is new is the thermostat bad? maybe stopping circulation somehow?

I think if you have compression in the cooling system, you can start it cold with the rad cap off, every time the leaking compression cylinder fires, you should see bubbles coming up in the water...
we did that with my nieces Plymouth breeze... every few seconds you would see a little stream of bubbles...

[1966burb]

I have checked for bubbles in coolant and nothing. I may pull the stat and test it. I grew up in a Union 76 station working on Chevrolets for years but have never seen one act like this. I googled it found guys with Corvettes, etc that have had same issues--- hoses blowing off, hard upper hose, but have not found any solutions.