24 to 12 volt starter conversion which starter to use

[bonedadyz]

was wondering which starter to use cause someone done started converting it and i think they put wrong 12 volt starter on it

 

[Mullaney]

was wondering which starter to use cause someone done started converting it and i think they put wrong 12 volt starter on it

.
A good starter / alternator should be able to convert most anything - but could you give us more details?
It is a CUCV, HMMWV, Deuce?
What kind of vehicle or maybe what kind of power plant is under the hood or behind the covers if it's a GenSet?