A word of caution on older batteries. They may pass a load test, and still not be up to cranking the engine over and firing the ignition at the same time. The last few times I have been out to the track, the car started fine cold off the trailer. No problem driving to the tech lane and teching in. Warm the motor up, drive to staging and shut down and wait for the call. Go to start up, good crank - no fire. As I would release the ignition switch to the run position ( drop out the starter ) the motor would try to fire. Cold motor & starter, no problem. Heat soak a bit in staging and the current draw went up enough to keep the ignition from firing the plugs. Starter draw was in specs. Voltage drop tests were all under .1 volts. Battery TESTED good. Installed new battery. Problem went away.