Thanks a1PCfixer! I was thinking old school on the early ignitions that required 4.8 volts. HOWEVER, following that link, Jody did make an interesting case or two for not using the higher voltages..... ? (shorter battery life at 6 volts and still more failures)

>>> While the Rcexl literature states the acceptable maximum input voltage range is up to 7 volts, it also states the typical voltage input at 4.8 volts. Two other aspects that are worthy to note are that the current consumption of the ignition at 6.6v input is double what it is at 4.8v, this means your battery will only last 1/2 as long. Lastly, as one that sees many, many engines and ignitions, I can tell you that the failure rate for ignition modules run with input voltage above 6.0 volts is roughly double that of modules run with <6.0 volt inputs, once you're able to see the larger volume sample size it's clear that <6.000 volts makes the ignition much more reliable and robust. >>>

Thanks,

Ernie