[kwtoman]

How difficult is it to upgrade a 36v 6x6 to a 48v 8x6? and would the battery compartment need modified?

[Frank7]

Aside from battery space you will need to make other radical changes to your system,
Most important is you will need a 48 volt charger.
Depending on the type of cart ( not mentioned ) there are more considerations.

[kwtoman]

It is a 2005 EZ-GO 36V that I am thinking of upgrading.