The ring gear is different as well as the starter drive gear. The ring is extremely difficult to find, but I came up with a guy named Al Suering in Pennsylvania that deals only in ring gears. I had to wait almost a year til he produced another batch of six and one day the phone rang and it was him ready so ship. The starter interchanges with the V8's, but the H drive gear has either one more or one less teeth. What's the clutch and transmission and what vehicle?