Brian,
The Hush Puppies will work well on your longbow, the bow hush is made for recurves because the string lays against the limbs, it does not lay against the limbs on a longbow. Normally installing the hush puppies at the 1/4 points on the string is the ticket, measure the string from where it first contacts the limbs, so lets say your measurement is 57" divide that by 4 which would be 14.25" so you would place the puppies at 14.25" from the point the string touches the limb on each end of the bow. I would take the puppie and count the number of strings in it, then split it in half, you do not need the entire puppy on each end of the bow, so one puppy would be enough split in half. Just saying how they work for me.