You can find the gauges many places. Snap On, Kent Moore, OTC, Ebay, Mac, etc. Prices at Mac or Snap On are ridiculous.
You need to know what injectors your 3-53 has to get the right gauge. All my 3-53s use a N45 gauge that sets them at 1.460". Costs $20 at:
Other places that sell gauges are . . .
I doubt the Michigan loader manual would have the info. You probably need a 53 series Detroit manual. I have one here somewhere. But even with the manual, you need to know what injectors are in there. When you pop off the valve cover, they well be marked.