@318willrun , wire back that 2nd carbs secondary air door and see if it helps any. If you check out the 1965ish Hot Rod article they did on the 273-8 that had dual AFB's...they did that for some reason. (im thinking it never opened enough otherwise)
Well, that would be like putting a screw in the slot on a holley vacuum secondary to make it open mechanically. You'd get a massive bog because of no accelerator pump on the secondary's
