i know its been done over a million times.
but i am trying to make my own. i have cut my 3-1/2 square steel down to 13" long. it is 1/4" thick.
now i have it cut into two by slicing it diagonally.i measured my 63" spring and it seems to be about 2-6/8" across or so....
now my question is to drill my hole for the 9/16ths bolt.
so if i lay the hanger down and measure up i want 1-3/4" ( half of how tall the spring eye plus leafs are ) plus my gap, plus 1/4" for the thickness of the steel.

then i need to leave HOW BIG OF A GAP for clearance for the spring to rotate ?
if i use 1/4" it leaves it way to low in the cut i have to make it worth even trying...
if i leave around 1/8" it seems to be okay but thats pretty tight.
but once the hole is drilled its not a lot of meat left for all that tension.

dont know if this makes any sence to anyone
i have my url for picture
https://www.yotatech.com/g/picture/5099910
does that even work ?.
thanks for trying to help.