The 60 of the EFH6-60 part number refers to the length below the head to one side of the helical slot locked position. If you look on Southco's website and dig quite hard you can find the tech sheets on them. The pdf below should show you specs on the Dzus fastener.
It is length L you are looking at. Look under the part number. Unfortunately the dimensions are in mm(because we are in the peoples socialist republic of europe) but the 60 means 0.6 of an inch I think.
I hope this helps.
Adrian I would like 10 I will take a chance with the size John Runyan 12635 Itaska Walk Milton Ga 30004 I sent a post to Jimmymac by mistake I don't know how I did that but I am not real good on computers Let me knowhow much with your return address Thank You !!!
A bit more ionformation for you, probably too much but anyway here is a chart of the pigtail receptacles and as you can see there a number of different offsets and sizes. https://www.southco.com/static/JDrawing/j-d4-s6.pdf
Even I do not know which are used on my car let alone the original cars
Your inbox is full and not excepting. Can you make up two with the wings brazed at 90 degrees to the original slot and fill in slot with braze material and left in a unfinished state that I will finish. Your size and shape are close enough to my originals. Give me a total for all. Steve
Unfortunately without having the dimensions of the Summit Racing fasteners I could not tell you if they are the same. Dzus fasteners come in different widths and lengths. The original one was about 5/8 inch long hence the 60 in the part number back at the beginning of this thread.
If you have a Summit one, measure the head diameter, the surround diameter and then the distance from the flat of the head down to the bayonet twist grooves at the bottom and post them back here and I can check.