If you really want a precise (custom) U-bolt, McMaster Carr (Chicago) will make them to your drawing.   Not inexpensive, but it's one solution option.

73,

Dave KJ9I

On 6/16/20 8:30 PM, Stephen E. Belter via AMSAT-BB wrote:

Joe,

Look for your U-bolts at an auto supply store too. The muffler clamps are different sizes than the hardware store clamps.

73, Steve N9IP