[RICK LAKE]

Grubby John 2 important things have been covered with battery cables and grounds. I would tell you to add a second ground cable from the block to the frame of the car. I run 3 on mine with the a battery in the trunk. Starter shield to slow down the heat soak of the starter. Jegs & Summit carry them. The better thing would be to get a gear reduction starter or mini starter. You would have to get it setup with the gear to flywheel clearance. It will spin over slower but will fire up any motor.
The other thing is to check the charging system and the CCA of the battery and have a battery test done. It is possible that your battery doesn't have a full charge after being run for 1 hour of driving. If you are running the 60-70 amp system and have under drive pulleys on the motor, the charging may be marginal at times with cooling fans on. You want about 14.2 volts with the motor running and no power draws.
There is alot of heat under the hood from the motor and headers. If you are going to stop the car for a period, I would tell you to pop the hood to help remove the heat. A small piece of 2X4 works great to hold open the hood. Rick L.