Gauge size for apron baty tray?
 

What is the sheet metal gauge for the battery apron on a 67? Need to replace some metal.

Prolly 16-18. But it's also formed, a formed 18gau piece is stronger than a flat 16 or even 14 gauge piece.

https://www.mustangsplus.com/xcart/Battery-Trays/

You can buy whole replacement battery trays for pretty cheap.

19 to 20 gauge in my experience. go measure your old metal (clean areas without paint and not around thin areas that have been stretched) in a few spots. report back what you find.

Guess I need a metal gauge..

a set of calipers would suffice.

ya you can buy the apron and the tray for under 40