How much height did you get?
If you used Delrin for the end plates then you might want to check for shift. Plastic does not do well with vibration. Eventually they will wear out.
if all you needed was an extra inch then these are the best deal around.
Charlie sells them cheaper than you can make them. He is a great guy and these aluminum plates are rigid as hell and will not wear out like the plastic would.
You also must be in great physical shape. Having the machine that close to the floor means a lot of bending over and use of the back and knees. Some of us here are not that limber anymore. 