69 c10 Rearend Issue

[69RustyBucket]

I have an 1969 c10 with 5 lug. I was installing my aftermarket braked 12 inch rotor to the rear. The 4 holes on the rear end were too small for the bracket that holds the caliper on. I contacted wildwood and they told me i had an odd reared and that i would have to replace rear end. What fits thats 5 lugs. My truck has a bolt on each side and the ladder bars. I had a bar going from the frame to where the lowering block is. Thanks need help finding a used rear end that fits