Yup, just going through the conversion now and I see the same. 4 bolt pattern on the 7 1/4 back plates, 5 bolt pattern on the 8 3/4, bummer. Plus the 7 1/4 is a 1.75 inch brake shoe where my new shoes are 2.5 for the 8 3/4. I was hoping to retain the 7 1/4 stuff since its 10 inch, but doesn't seem like an option now.