Thanks again Rich
as always, you've been very helpful and informative
The Aux battery that I intend to install right behind the right hand side head light fits just like you said.. positive terminal is at the farthest possible point from the body.. If I try to fit the other battery i have as a primary the positive will be very close to the body so I guess I'll leave my current battery as a starting/primary battery and the optima deep cycle as an aux battery..