Hmm... I guess I'm crawling back under the car tomorrow and I'll measure again. That's awefully close... IIRC, mine was just a hair over 1", but then again, that's not good enough. Thanks for the link. I'll look it over when I'm done here. I have a 489 case with a 1 3/4" pinion nut. I also have a bolt hole for one of the cap straps.... the previous owner must have drilled through when the hole got stripped. PLEASE don't tell me I have a grenade!!!!!!!!!!! The last thing I want to hear now is that I have to start rebuilding the center section!!!!!!!! :shock: