mamba monster on 7s

A friend accidentally took my 4S packs which he thought were 3S and hooked them up to his E-Revo. He even ran it for about a minute until I saw his mistake. Not sure what sort of long term damage he might have caused but it did run. You could get lucky and it will work fine or it might go puff as soon as you connect the batts. Either way I wouldn't do it. I hate destroying things for no good reason at all.

Have you considered an plane/heli high voltage ESC. As long as you don't need reverse you could make the whole thing work with a use of a PISTIX. Plane ESC can usually be had much cheaper than a car version so might be worth going that way.