The approx. dimensions are: 1/2-20 UNF-2A thread, 3-3/4" Length, 5/16" Bolt Hole Diameter. These forks are priced and sold individually, not as a pair.
The opening from the top from hole to hole would be .210". Measuring from the bottom opening width would be .623". ID of the hole would be .312".
The width of the slot is approximately 0.2188 inches.