Center height of bars is 2.500 inches (see photo). The "T" part of center bolt measures. 750 inches thick and it's 3.500 inches wide but is machineable and could be modified to fit your lathe compound. It's big and heavy (about 25 lbs) and was for a larger swing lathe.
It was used on 24 inch swing lathe. The item "Armstrong boring bar holder" is in sale since Monday, May 15, 2017. This item is in the category "Business & Industrial\Manufacturing & Metalworking\Metalworking Tooling\Toolholding\Boring Tool Holders".
The seller is "jett1400" and is located in Whittier, California. This item can be shipped to United States.