When Sears had a "sears" labeled battery, I had very god luck with them, but I have never had any luck with the DieHard series though I'm sure many will have not had the same experiences. My personal favorite is Delco with a lifespan of 5-8 years in just about anything I have put them in (including one vehicle that had a 10.5 compression ratio with 180 psi in the cylinders). Champion also makes a very good battery from everything I have read, an friends have experienced. Motorcraft....good for about 3-5 years.
But yes, a good quantity of reserve cranking power is what I look for, I prefer at least 600. Yes high CR engines do require more CCR's because the draw is greater but what your friend has is more than adequate in terms of ratings. What can also help very much is to put a switch that cuts off the ignition so that you can spin the engine with the starter first, then give spark second which reduces the load on the starter since the engine is not firing...
But yes, a good quantity of reserve cranking power is what I look for, I prefer at least 600. Yes high CR engines do require more CCR's because the draw is greater but what your friend has is more than adequate in terms of ratings. What can also help very much is to put a switch that cuts off the ignition so that you can spin the engine with the starter first, then give spark second which reduces the load on the starter since the engine is not firing...