I have a 76 miller with a ford 460. I took out this weekend and after running it for about 10 min it died while running. I tried to start it and it sounded like the battery was dead. I pulled it off the water then it started right up. Put a new battery in it put it and it ran for about 10 min then died again and sounded like the battery was dead again. I got the alternator checked its fine and battery is fine. Anyone have any ideas?
Not without a whole bunch more information.
Water in the oil? Fuel pressure? how old are the fuel lines? Condition of the fuel tanks? What type of fuel pump? What ignition system?
Water in any cylinder will do something similar to what you describe.
A failing ignition coil can cause it to die, but the hard crank thing is weird.
Running stupid hot will do strange things.
A major electrical short will do what you explain...
The work is on you buddy, get some information together and we'll see if we can guess that issue...
As of right now, you could have boogers in the carburetor.

GT