Gear Ratio

[TomC]

Whatever is surmised about whether or not the 6V-92TA will over heat compared to the 555, you should still upgrade your radiator to the largest possible.  Nothing worse then overheating on a long grade-especially with no turn outs.  I'd still like to know the dimensions of the current radiator core.  It will be much easier now to take care of then later.  Good Luck, TomC