marine alternator
 

Is there any reason one cannot use a marine 10si or 12si type alternator on an automobile application. I know the reverse is not recommended, but I cannot find anything addressing this question.

It will work fine. The reason auto units are not used on boats is because of marine laws. Spark arrestors etc.

Then it's safe to assume they are essentially the same internally; only difference being the spark arresters?

Marine 10/12si alt/
 

Use to rebuild alts, all types. the marine has spark arrestors as mentioned so no diff. But some are 1 wire alts, pos. batt trem only and don't have an ign keyed wire but field themselves with Rpm, so if used a smaller pulley may be needed to initially start alt, that way you won't have to rev it up to start charging.:thumbup: