The ratty one is my original from 70 Super Bee with power disc...the nice one I got from a buddy...was supposed to go right in...but the fire wall studs are 3/8 instead of the normal 5/16 and they are longer...with the 3/8 studs it won't go through the holes on backing plate or fire wall. I've had a few of these boosters before and don't remember having this problem. The boosters otherwise seem completely identical. What gives???