In the 1st pic, the area between the two black marks is where there is interference.
As you can see in the 2nd pic, the B302 bracket drop is only 1/4" and about 11/16" of drop is needed to clear the bottom of the Summit carb.
The drop section of the bracket is 0.83" wide and made out of 0.10" thick steel. I found an old galvanized switch plate that is 0.068" thick and will add about 1/2" of drop ... also verified that this added drop will not hit the intake, lots of room there.
I'll cut a 0.83" wide section out of this switch plate and weld to the bottom of the B302 bracket using an old carb base as a fixture. After welding, I'll cut the center section out of the B302 bracket and add more weld to the top / cut ends. Then touch up the bare steel edges of the drop extension & welds with cold galvanize paint. As this is under the back of the carb, the mod will be out of view and it will still look like a stock / un-modded Ford bracket when installed.
Doug