Quantity   Component name
2 × 14mm all metal Spur gears. 1st attempt we used nylon gears. immediate failure....they melted.
1 × Pump block. Made with lathe. Will publish plans if asked. You can check on google for images to have an idea but you will need to turn it to your gear's size
1 × Misc plumbing. (In and out pipes, depend on pump block and flow needs)