If you want the bolt to slide through the hole a 5/16 hole will work well.
For a clearance hole you need a 9/64 drill bit.
quarter inch drill bit
Bolts are categorised by their thread size. The standard socket size for a bolt with a three quarter inch thread is 1 and one eighth inches. Heavy head bolts use a one and a quarter inch socket.
A 1 1/4" wrench will fit a bolt of the same size .
A 3/16 drill bit.
You drill the proper size hole in to the bolt and remove it with an E-Z Out.
2,3mm
That size is correctly 0.375, and is equal to 3/8 of an inch.
An 'O' drill bit is a decimal size, 0.3160 inch, which is between 5/16 and 21/64 on the fractional inch scale.
The 'R' drill is 0.339 inch, which converts to just a tiny bit less than 11/32 of an inch
There are several bolt and nut sizes associated with the 1997 Chevrolet truck bed. The bolt and not sizes range from a half inch to three-quarter inches.
For coarse threads (13 threads per inch) use a 27/64 drill