Q- jet Air cleaner bolt

I need an air cleaner bolt for my 72 gs ( double end thread) what size are those threads, and how long should that bolt be?

 

You can use threaded rod, cut to size. I think thread is 1/4-20 , and generally about 4 inches long, but cut to fit..

 

Correct 1/4 - 20 it is. Cut to length .

 

also called course thread.

 

The right recycling yard with some 35 to 50 year old Detroit iron could have oodles of these.