Radiator Hose keeps blowing.

I have a 1966 Mustang, with a stock 289 V8 and a three speed auto tranny. I recently blew the top radiator hose right next to where it clamps into the radiator- no big deal, I took it off to replace it. The nozzle on the radiator was almost pinched shut, so I hammered it out as smooth as I could and put a new hose on. That day I blew the new hose in the EXACT same spot. So I figured I must not have smoothed it out enough so I pulled the radiator and took it to a radiator shop to have them take a look at it, the guys fits a special ballpeen hammer in there and gets it almost perfect. So I put the radiator back in, reconnect all the hoses and tranny lines, and replace the top hose. Two days later after very very easy driving, I blew the hose in the SAME SPOT. What is happening to my car? Oh, and also, for some reason after I replaced the first hose, my car makes an incredible thumping/rubbing noise if I give it a ton of gas. Any thoughts?