Don,
Yes, you can use the item pictured as 'this' in .250...which of course is 1/4". They just shove on and will hold tight. As Tim notes, I think there is a connector available but the 1/4" quick connects will work fine.
I have heard the primary lead wire, which is from key to coil must be 10 gauge for these HEI units. I ran one for years and didn't use a wire that large and had no problems.
The quick disconnect tab you have pictured won't accommodate a full 10 gauge wire, it's too small. The 'yellow' disconnect that will accept a 10 gauge wire might be too large to stick up into the HEI cavity and will be too large for the tab! You might have to improvise!
Stuart
