When we ran a full service chassis fab/turn-key hot rod shop a number of years ago, it was always useful to have threaded things around to weld into the frame for some kind of mount, etc.
Here’s a list of all our threaded things for your reference:
Front C Notch Fill Piece for Rack, EA
Product Details
Brand: Welder Series
MPN: 12202
Country/Region of Manufacture: Canada
Thickness: 3/16"
Used as a filler for the front c-notch for Mustang II rack bellows clearance. Priced individually.
3″ ID x 2-1/4″ high arc x 2-3/4″ wide.