The "fins" are scooping water towards lower radiator hose outlet...

 

Maybe this helps..

 

Looking at your paper drawing the impeller would spin counterclockwise to pump.

 

So reverse rotation? That's what I need or my march serp kit

 

Google it, you'll find pictures

 

I have googled it. There's a lot of conflicting information out there. Like this pic here. Looks like the same damn water pump to me..

 

Who's pump is it, any numbers on it, what drive set up was on it to begin with? The last would be the best way to determine if it is standard or reverse rotation. But my best guess would be it is a standard rotation. The water flows only one way through the block, what makes it standard or reverse (from what I know) is the direction of the drive belt.

 

Assuming the drawing is of the vanes as seen on the back side of the pump, I believe you're right, it would turn counter-clockwise as viewed from the back. But that would be clockwise as viewed from the front, which would make it a normal rotation pump.

 

That is a standard rotation pump. The biggest identifier is the three bolt pattern around the water outlets. Some standard rotation pumps did only use two bolts.

Standard cover on left and reverse rotation on right shows the bolt difference.

 

There aren't any part #'s on it, or any name on it. It came off my 351w with a march perf serp belt setup. The kit calls for a reverse rotation water pump, but the PO put a ribbed water pump pulley on it. which was wrong. The water pump pulley made me think that the PO put the wrong water pump on it. Which it is looking like its correct.

 

The pulley bolt pattern is also different between both so pulleys can't be interchanged and be turned the wrong way.

If you have the standard rotation timing cover buy a 86-93 5.0 Mustang water pump. Its reverse rotation but it works with any timing cover.

If you have the reverse rotation timing cover buy a 87-96 5.0/5.8 Truck water pump.