will 73 up rear end fit??

[Kid]

Does any body know if a 74 chevy pickup rear end fit under my 68 C-10 short bed?? I know that I will need to remove and add the correct perchs, but I am concerned about the width. My 6 lug measures 55 1/2" backing plate to backing plate, I found a 74 rear in the junk yard for $100. it measures 55 3/4". This would be cheaper than buying the axle conversion kit.