Hi there! Thank you for posting a question about the American Granby PMB1 Pump Mounting Bracket Stand. This pump mounting bracket stand has dimensions of 7-1/2" x 9-1/8" x 1-15/16". About the 3" height that you need, sorry, the American Granby PMB1 doesn't have the size that you need, sorry, American Granby doesn't have that size. Please don't hesitate to contact us if you have any further question about this product. We thank you for choosing PlumbersStock.com. Have a wonderful day!