Calming Down a 6v Starter on 12v?

[markdtn]

On my Avatar 2N tractor with 8BA I started with a factory 6V starter used at 12V. It did seem to hit a little hard so I bought a '63 390 Thunderbird starter that was 12V to begin with and used the flathead armature and drive in the Thunderbird case. It worked like a charm.

Then I put the engine in another tractor (8N) and bought a Powermaster mini-starter so I did not have to cut the transmission case/bellhousing on the tractor. They are kind of nice but definitely not period correct looking.