[Healeys] backup fuel pump polarity

[T W]

I'd like to add a backup fuel pump to my BJ8.  All of the small pumps I've
seen state that they're for negative-ground cars, and my car is a positive
ground car.

If I get the polarity of the wiring right, does it matter?   Or am I going
to short something out thru the pump body?

thanks,

Tom