I've got an 8v battery in my 53. After tweaking the regulator it has been doing just fine, no unusual problems with the bulbs either. That said, if you need a new battery do as Cletis says, go back to 6 v. My guess is that your guy (and my Napa guy) had 8v batteries in stock but no 6v. Those 8v things work well on the farm, so why not in a truck? That is the line I heard...
I would wonder if the trickle charger is too fickle, I charge my 8v with a standard 6v charger.
Karl

It may not be the easy way, but it is the Cowboy Way - Ranger Doug
Beware of the stories you read or tell; subtly, at night, beneath the waters of consciousness, they are altering your world. - Ben Okri
1953 Chevy 3100
1960 Volvo PV 544
1941 Chevrolet Special Deluxe