I don't think the water pump will take anywhere near 3hp. But, soon we will know exactly how much power it'll take.
I worked on the mount a bit the other night. There ended up not being enough room above the engine mount on the Metro, so I'll have to mount it under it. I actually decided to use the engine mount as the mounting point. Its the part that is rigid to the engine, so it should work out well.
I started out with two pieces of angle iron. These will straddle the engine mount.
Two slots were cut for bolt clearance. I oversized them and slotted them for adjustment to get the belt to light up.
Here is the test fit on the car. My mounting plate gets sandwiched between the two motor mount pieces.
The vertical part of my mount will continue down, and then flare out. The flared section will have holes for the motor to mount to.