You really need to contact the converter manufacturer for the correct part. You may have the wrong converter as well. Ordering from Summit and asking us for the correct parts isn't the best thing to do.
No, their converter is fine. It fits a 727 Chrysler transmission. He just needs the correct flex plate with the balance weights for the 360/5.9L! This is not rocket science. Get the ATP Z-332 and bolt it together.