When installing the valve assembly on the center link the collar bolt is on the bottom so that means the compression pin gets installed throughout the top? That means it has to go through the long slot of the valve assembly and into the pre-drilled hole in the centerlink? Typically what is the length of the pin? Found one at hardware store which fits the hole but available in 1/2", 3/4", and 1". So which is close to The correct length.