I learned this trick from Bob Barrows. Rather than buying a shorter pushrod, you can shorten a pushrod by using a hacksaw. I used a 32 tooth hacksaw blade to remove a kerf width of the aluminum pushrod, adjacent to the steel end "button". You can tell you're deep enough because the steel is smooth and hard in comparison to the aluminum pushrod. After the hacksaw blade kerf width has been removed, I tapped the steel button down using a brass hammer, with the other end on a piece of wood. It took about 20 minutes to shorten two pushrods.
Starting the process hacksawing next to the pushrod end "button".