You had your answer in your first sentence. An old time V8 guy. This was a very old time fix for mechanics ( and Farmers) in the 40s and 50s, who had trouble starting their equipment. In very cold regions it was a legitimate fix, but for most it was a way to ignore the problem of slow cranking, ie, starter not working properly, battery cables with too much resistance, sub par battery, poor connections, etc. 99% of the time, a 6 volt system in good working order, is all that is needed for stock vehicles. Thats been my experience, and I'm OLD.