Alternator charging, need help

It will run either way. Only issue I know of is the cooling fan. You CAN buy reversed fans for some alternators. The old Corvair generators/ alternators is one example. If this is on a race car, the fan is not an issue. We ran a standard Delco/ integral back in the 70's running backwards on our old Allis model M crawler, driven off a pulley on the mag drive.