does anyone offer early A small block shortie headers

Those look similar in design to the shorty headers allowed by IMCA. It would still be their call as to if they will allow them. I would assume you will have to be on 2" pipes with turndowns like the chevy open motors. You will likely be required to use the Schoenfeld 3" to 2" reducers also.
I hope the Sanderson's are available at a cheaper price uncoated. Here is a link to the Chevy IMCA version.



Schoenfeld IMCA Hobby Stock Headers