1964 - 1966 Barracuda starter removal and installation advice

there are 2 different spec RAM style starters. One is rated higher than the other (1.4Kw base) with an extended motor section. Both will bolt in. Saw the comparison years ago somewhere and now I cant find it Its obvious when looking at the 2 side by sie, one is about an inch longer in the motor section. Those are some powerful starters, 3600 rpm no load. Big block ready!