8 3/4 Rearend Question

Has anybody here actually MEASURED the width of a stock A body 8 3/4" housing? I have a chart that says it's 51.4" wide & I'm wondering if anybody can verify that dimension. I have a guy who is going to build me a narrowed housing & I know how much narrower I need than what I have now but I'd like to be sure of the width of the stock 71 A body 8 3/4 rear I have. I can't get an accurate measurement of mine without pulling the pig & the backing plates & once I do that it makes the car really hard to move around until I put it back together. I'm trying to save myself a few steps.:-D Thanks for any help you guys can give.