whats the shear rating?

The shear strength is virtually irrelevant. There is next to no force against it by the lever. It just keeps the lever from popping up. A good twig or wood dowel could do the same thing.

What is the shear rating? I would be using this in pla e of a bolt un a weight lifting bench. The rack is supposed to hold 600 pounds.

This pin is only used to "lock" the clamping mechanism and as such has no relative shear rating.

what is the dimension from the shaft to the wire (looking for clearance of 1-3/4" )?

From the Amazon Product Dimensions: 7 x 2 x 2 inches. The 5/16" shaft would make the gap less less than the 1-3/4" you need, but you could bend the wire part as needed. It's really flexible and easy to bend.

ASIN	B001GN6YS2
Best Sellers Rank	#12,485 in Automotive ( See Top 100 in Automotive ) #10 in Trailer Coupler Parts
Color	SILVER
Date First Available	August 3, 2017
Exterior	Painted
Finish Type	Zinc-plated
Global Trade Identification Number	00612314610013
Is Discontinued By Manufacturer	No
Item Weight	1.6 ounces
Item model number	25010
Manufacturer	Curt Manufacturing
Manufacturer Part Number	25010
Maximum Shear Strength	[HIGH]
Model	5/16" Safety Pin
Number of Pieces	1
OEM Part Number	25010
Product Dimensions	7 x 2 x 2 inches
UPC	612314610013

CURT 25010 Trailer Coupler Pin, 5/16-Inch Diameter x 3-Inch Long

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