I have a 48" Dumas pt boat and I would like to get opinions on these two props.

Dumas 3 blade brass 1.5" dia. 2" pitch prop.
or
Dumas 3 blade brass 1.75" dia. 2" pitch prop. Thanks, Randy

Depends on how many volts you are going to put into those motors. If you actually run them on 12V and don't 'overvolt' them like so many of us do, I think they should swing those 1.75" props easily enough.

I was thinking about 12 or 14.4 volts.

I was looking on the net somewhear and I read about a 48" pt with Grapner 12v 700 motors which was said it run well, he never said the props he ran, does anyone know of this thread, I would like to ask about the props, thanks, Randy.