1970 barracuda front hub size for drum spindles

I am looking at putting my own brake kit together and am looking at srt rotors and benz rotors. I am looking for what size OD is the factory hub where the rotor will sit? I am trying to close the deal on a set of SRT8 calipers and need to let him know before I make it home tomorrow. If I can work this out I will post any info I get on here.
Thanks

This may help a little, 70-72 is smaller
Contact Dr Diff, he makes an adapter and will have the dimensions.

I am looking for the inside diameter of the front drum where it centers on the hub. I didnt want to waste Dr. Diffs time and not buy from him

Just got home and pulled mine apart looks like 2.81" the inside diameter of the Benz hub is .172 smaller so should be easy to bore to the correct size. I committed to the rotors also